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POPULAR Choice
INTRODUCTION TypeGuestions
BIOLOGY

1.What is
biomimicry?

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a) A type of science
b) The act of mimicking nature [MODEL QUESTION)
for technology¥
c) Copycating nature
Chapter at a Glance biology.
commoniy Idenied
by the
by lun
uman Genome
to deternine many
Answer: (b)
the human body and bases in

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in
molecular revolutions of bases
proteins and of
of 2.Leaves inspired something
and
Cenomicallowed cids in prorens
in acids a) True b) False
Project, has us to identity' all
0 of amino acids
sequencing tne use or
computers to analyz the [MODEL QUESTION]
sequences. Our
bioinförmatics. which
on
relies
derstanding of
understanding the in
ol the ft Answer: (a) c) none
d) both
r diIdual
developnment of
puted the for pattems and similarities. The
subsequent
of a comprehensive
information
Parts List." ellular
ucnces the
creauou manipulated. These advan
manipulated. advances in the 3.Examples of biomimicry are:
sequences resulted in identified and a) Sun---sunflower MODEL QUESTION]
underlyiny the easily
components can now be knowledge to our toolkn
ana spurred the growin a nte ce b) Whale-turbine
l0OK at biology
from d c) Gecko--Gecko tape
cular
understanding of biology added
much
time, we can biological fiunctiC e) Horse--car
d) Elephant trunks---robotic arm
engineering. For the first operation of
The
Deween biology and attention to detail.
regulation of biological
funet Answer: (6)
much greater ctions
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pcspective and with a "biomolecular, machines. he
complex
now be understood as "biomolecular circuits. 4. Human genome project was published in MODEL QUESTION]
can be seen as complex
solicit ne knOwledge and practica
lical a) 1999 b) 2008 c) 2005 d) 2002
many areas today that
a few of the Answer: (c)
The following slides show
to changes in
skills of bio-engineers: tlexibility, durabilitY, and endurance
1. In the past. only
mechanical aspects such as Now, bioengineers incorporat
rate 5. In 1857 it was proved that all fermentations are results of microbial activity by
spacestHis. [MODEL QUESTION]1
considered in the design of
Outside conditions were body into the finalization of their designs.
knowledge of the physiology of the human b) Lmark c) Darwin d) Mendle
suits, the design and implantation
ot hip implants was previously a) Pasteur
2. Like the desiyn of space
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engineering. The mechanics and movements of the

hip wvere studied Answer: (a)
solely a branch of mechanical greater emphasis is placed on the understanding of [MODEL QUESTION
substitute. Today.
to produce the best metal suitability. Use of living organisms
6. to serve humans is
b) Social biology
bone composition and tissue-impant
the body regardless of intervening bone by means of a strong
magnetic a) Biotechnology
3. MRI produces images of d) Service biology
field and low-energy radio waves. c) Human biology
in the Langer lab at MIT relies on knowledge ot Answer: (a)
4. Controlled-release drug delivery as explored [MODEL QUESTION]
enzymes and whether certain polymers/drugs would be degraded by them.
the body's
. Protein content called novel is produced by using
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5. Image-guided surgery records surgical processes with greater detail and allows doctors Virus
Micro-organisms
consult past steps for comparison and completeness. a) Bacteria d)
6. The quest for an ideal replacement arificial heart continues to bafle the scientific communt c) Fungi
In the past, engineers devoted their efforts to designs based on nonbiological materials. They
Answer: (d) of yeasts,
pure culturesQUESTION]
met'with repeated 1ailure as ine complex biological systems of the body formed blood Cio rom mixed or
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extracted [MODEL
signal rejection of tTOreign supsances such as metal, plastic, content which
is
ineers are exploring ways to esign hearts out of biomaterials and polyester. Today, bi0l0 rotein fungi is cal b) single cell
protein
protein
and possibly other tissucs and
7. Bioprocessing ne s Oedure of preparing a biological DIological material, especially a pproau
bacteria, algae
protein d) tetra cell
of genetic engineerins, for commercial use a) triple cell protein
8. An increasing empnasis is placed
on
envi
Onmental bior c) double cell
processes must be environment friendlv that all chemica Answer: (6)

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POPULAR PUBLICATIONS many of the problem we
splved are
mistry, tra nsportation,applingwith: BIOLOGY
Type Questions ol, benign
cont
Short & Long Answer ,
collaboration,energy,
y, food
andmore. producti

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three climate
and
engineering?
[MODEL QUESTION] What are the. els of biomimicry?
between science 6.
1. w the relationship Answer:
syntheo Bionimicry can work on three levels: [MODEL QUESTION

Answer: doing. SCience iS esis of organisim,

engineering is about
SCience is about knowing and Is "the application The
law of nature, while engineerg behaviour, and
OWledge by understanding the use the scienii Its

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for serving people. Enginees ecosystem.
AnOwledge to transform the nature engneeTS and scientic The
structures and equipment. Botn Buildings on the organism level mimic a specific
ROWledge to build processes, mathematics and technology, but
engineers are trainoed organism
ave sound knowledge of science, creative solutions to the cnanenges. Sclence is abo biomimetic design?
o Use these principles in designing ne ver was, Science and 1. What is
is about creating what
udying what is existing, engineeringother, for to transform nature ellectively require A er: r
[MODEL QUESTION]
Cngineering. both complement each Biomimetic refers to human-made processes, substances.
instrumenS to modify it in devices, or systems
proper understanding, and to discover nature's secrets requires The art and science of designing and that imitate
experiments. a aS biomimicry because they mimic biological
building biomimetic
apparatus is also
systems.
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2. Why Biology is important for engineers? [MODEL QUESTION
8. Similarities between Camera and eye? [MODEL QUESTION
Answer:
Biology may not be a typical subject in the traditional engineering disciplines (i.e., civil Answer:
electrical. or mechanical), however, it is a fundamental component of disciplines such as Those who are wndering jUst how similar a camera is to the human eye will be shocked

biosystems engineering. Biosystems engineering -emphasizes the application of. to find out the functions ol a camera that work just the same.
engineering principles to biologically-based systems (i.e., systems that include plants, The shutter in a camera can be compared to the iris in a human eye. It controls
animals, microorganisms, or humans). how much light is able to enter the lens.
The lens in camera is similar to the lens in the human eye, which are both used
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3. What is the difference between bioengineering and biological engineering? to focus light and create an inmage
In the human eye, the image is
Answer:
[MODEL QUESTION] With a camera, an image is recorded on a film.
the caimera stores the image one ime and the retina
Bioengineering focuses on the application of engineering displayed on the retina. However,
agriculture and environmental processes. On on biological processes, food, Isconstantly passing information along.
the other hand, biomedical it would be 576 megapixels. As of yet, the
focus on the application of engineering
to biological and medical
engincering is the human eye were a camera,
sciences to improve produced is only 50.6 megapixels.
healthcare delivery systems highest megapixel camera ever
[MODEL QUESTION]
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4. What is Biomimicry? Camera and Eyes?

Answer: [MODEL QUESTION]
.What are the differences between
Answer: eye is
Biomimicry is an approach to Simply speaking. the human
measuring of light: our brain to create the
innovation that seeks ADSolute versus subjective im harmony with
challenges by emulating nature's sustainable solutions means that our eyes work through the
time-iested patterns to human oecive device. Our eyes are adjusting the tocus (by bending the lightour brain can
This
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products, processes, and and strategies. The

earth over the long haul.
policIes-new ways of goal
living-that are well-adaptedis to create
to lite on es you perceive:
eyeballs) and
translating photons (light) into
all about our brain:
an electrical inpulse
ft is continuously
readjusting its

5. How do we use biomimicry?

Our From there onwards, it's
context. In otner
woras, Our eyes know what must

Answer:
Ss.
colou according to thelighting
Biomimicry is learning from [MODEL QUESTION] alance black elc.
cen as red or white orhand, measuremem devnce- It is
measuring the
recorded need to
and then emulating is an absolule ana signals
ecosystems to create more on the other sensor is dumo. the
circular designs.
The core
natural forms,
processes, and light era,hits a series of sensor, but the
temperature or tne ingnt
numH1atng the Scene,
for example
idea is that nature nat
has alrC suit the color
to
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to use i omimicry
Airplanes DCgan as oncept. BIOLOGY
POPULAR PUBLICATIONS focus. In
In our Shape and mode offlyinga conce Engineers
froin the tilm lo eyes, their wingS, lookeda
moves closer/tiurther shan men birds and
tocus: In camera, the
lens eyes
muscles in our
change the actual vings and bodies that looked almost ike a hiie,
ns
Le
focus: The
i the
roblem that had existed in the S The shape
able to form
plane

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ens
lens
changes shape to
inside our eyes. unitormly sensitive to
ignt. lhe human retina
is
ontinent to tinent, and he u E Human beings
Snape of an animal
of birds helped
needed way
a
to solve a
to move from
mo
a camera is power, our eyes in accessibility trade,
ensitivity to light: A tilm in quality image and capturtng havea solved problems business, and to inspire an invention
that nas
O.Theretfore, with respect to of transportation.
locations than a typical
caner
capture easil. biology in our life.
reater sensitivity in dark digital cameras cannot y: The 14. Role of
that a current
nere are lighting situations
noise: AS an example when Answer: MODEL QUESTION]

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in a barrage of digitat
come blurry. or you
out
potos will fluorescence image of cells under a microscope, tne image can sea with Knowledge of nature
OOserving a
nigh-on impossible to capture for
an ordinary camera. This is mainly R f biology helps one understand the nature around. One can
Our eyes would be our eyes) is so low know what an animai,
light entering the camera (and lant. microbe, etc. It also teaches the structure of diferent
because of the fact that the amount of parts of plant and animal
adies. It explains the processes like reproduction, metabolism, food collection.
[MODEL QUESTION] etc. in
10. Write the principle of flying. detail.
Answer:
ACCording to a principle of aerodynamics called Bernoulli's law,
fast-moving air is at
Benefits to man.
lower pressure than slow-moving air, so the pressure above the wing is lower than the
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Learning biology can help one understand the benefits of nature to man. We can learn the
pressure below, and this creates the lift that powers the plane upward.
source of our food, milk, meat, eggs and other essential in details. One can also learn how
construction, travel, etc. For centuries man relies
11. What are the 4 principles of flight? [MODEL QUESTION nature contributes to agriculture, house
Answer: on animals for travel.
Principles of Flying
(1) Lit Role in medicine disease better. A
(2) Gravity force or Weight understand the concepts of health and
Knowledge of biology helps one physiology, etc. This helps to
(3) Thrust. and is the body made of, its
student gets an idea of what improvement. It also helps one understand
(4) Drag
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chances for
understand disease state and also are used for medicine.
Most of the
plants and animals which
Lift and Drag are considered aerodynamics the useful substances from biological knowledge.
forces because they solution by
movement of the Airplane through the Air. exist due to the disease condition find a

12. What are and landing on other

the factors of flight? Contribution to research: Even space exploration
to research.
Answer: [MODEL QUESTION] contributes a great deal
All Four Forces Act on an Airplane OlOgy knowledge of
the use of animals.
planets can be done by can be done well by
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When an airplane is 1lying biomedical studies bombs

straight and level engineering and capabilty of powerful
balances its weight, and the at a constant Lydrugs, the destruction
that even
thrust it produces speed, the lift it proau initeresting point is
of forces changes as tne airplane rises balances its O1Ogy. The
and descends, drag. However, this balan Was done by the use of animals.
as it tums. as it speeds up
and slows down, andendangered
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Conservation of natu which are

13. How do birds inspire Safe guar tne species conservation is
airplanes? ard and biology, we can understarnd EvEn tne soil, forest
Answer:
There have beenimany.changes [IMODEL QUESTION
By kOWledge of them from
extinction.
survival. For
in airplane them. This saves in human
ure. Engineers nave
been drawing designs since Unacistalid ietr roie
biomimicry to inspire their designs their ideas innovatior possible due to biology botany makes us
tion, development and in
usand years ago, and they even from nature, plant inimportance ofplants.
Study of the plants
and they haveave been using [MODEL QUESTION
trie gs details go through the study off Biology.
.

of ther fel and hurt themselves, have

aing planes, been trying to fly since ovet * importance of
kites and Write the
flying 1from clifis. Most 15. What is biology?
bio
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POPULAR PUBLICATIONS Answer: BIOLOGY
ineluding
ience and engincering both relat
descriptive
studies ife and
ving organisms,physiol 1orking vith;similar de
h iptive models models
Answer: neraclions, physiologica and to physica
the natural
science that moleculkar d engineering arc. In practice. similar physical
eninterinixed, Sical systems. sometimes

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processes, ther are
h astructure,ehemical coniplexity or the science, scientists thhe accomplishments of ver, Science
Despite the (therpopular usaue
development and evolution. single.
conerenm tield. Bio Nonctheless eers (tnere
5Cs
CCisms. eonsolidate it into
a
heredi ckct scientists). are many
rocket engineers.
to
unitying concepts that ne DsCunit of
ea ecognizes the cell as the
basice unit
that propels
of life.
the
genes as
creation and extinction of species.
Li
ing
nature. Understanding and engineering
this dilference
12 of the relalionsnip between is essential
differ radically but no
if one is to form
in their
evofution as the engine that survive by transtormg energy and decreasing the her in
possibilities, whether in molecular systems present knowledge and future a ciear

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Organisms are open sy stems as honmeOstasis. engineering technological
vital condition defined How do science and engimeering ditter! In
or elsewhere.
entropy to maintain a stable and kind or
cll research methods employea and the arts with a physical a sense,. they
Sub-disciplines of' biology are detined by the quantitatia system and seeks point in opposite
direcion's.
biology uses mathematical methods to tormulate SC ie theory. to develop a descriptive
Engineering starts with a descriptive
sstem studied: theoretical model- a
enpirical esperimens to test'the validity of S oks to develop model- an engineering design
models while experimental biology performs life and hou and a physical system.
In this, they
thevries and understand the mechanisms underlying are opposites. and from this
proposed differences in thought and goals. flow
and evolved trom non-living matter about 4 bilio ycars agO through, a deep
t appeared Consider how scienists and engineers choose
their objectives. A scientist
gradual increase in the complexity of the system. focuses on
what is not yet understood, and studies il. An engineer focuses on what is
already
1understood. and builds with t. Scientists seek simple
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Biology is the exploration of life. Researcher examine the structure. work, development systems that challenge their
Starting point. advancement and appropriation of living beings. understanding; engineers seek to build to build systems of challenging complexity using
Biology is important to study because understandable components. Where a scientist may contemplate solid-state physics and
-t helps uS get a better understanding about the world in its natural processes seek to unravel the mysteries of correlated electron phenomena. an engineer will use
t is the study of how lives evolves. survives and changes
-it gives knowledge about the interaction of cells with organs and organism
established principles of solid-state physics to describe the behavior of a set of reliable
designs for wires, transistors, and capacitors. A scientist may discover phenomena that
environment and ecosystem. enable the creation of a new transistor-like device: an engineer may discover how to
lt teaches how various organs and system works on human body
and how everything is organize a million transistorsinto a new information processing system.
connected in our body. provides an
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The molecular warld has been the province of scientists. Their knowledge
-t is an imnportant subject for medical point of view which includes in the molecular world will raise questions that
and its cure. identifying disease essential guidc, and engineering efforts
doing the work call themselves
Knowledge of Biology helps making a better spur further iscientific study. Whether the people
environment to live in. is of little importance. Regardless of
labels. progress in
Despite the profound advanes SClentists" or "engineers"
made over recent decades in technology, will require an
like that in other fields of
fundamental processes, some
basic problems have remained
our understanding of life s Oecular systems engineering;
major unresolved problems unresolved. One of th: engineering approach
in biology is
particularly its key processes the primary adaptive
function of sex, an
Process and the Scientific Methods.
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in eukaryotes
One view is that sex evolved of meiosis and homologous
primarily as an adaptation recombinati01 . .Compare Engineering Design [MODEL QUESTION
diversity. An alternative that promoted increased
view is that sex is an genet
repair in germ-line LDNA, adaptation for
Answer: products.
and that promoting accurate create new tihings. such as
that may be useful in the long run. increased genetic diversity is D nature works. engincers dilferent
primarily a by prod study how and scientists have
Another basic unresolved SCientists riences. Because engineers
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perform experiments
there is no consensus view on
problem in biology
is the biologic websites, environments, an processes in their work. Scientists
the underlying basis of aging. objectives, they follow different enginecers folow the
creativity-bascd engineering
are outlined in Ageing Theories. cause of aging. presc
At reas.
Various competilng USing the scientifie methou:
tne
scribe the relationship design process.
between
science and
engineering?
[MODEL QUESTIO

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as SCCn n tle diapram BIOLOCY

dn nto a series of stejs, Detne the problem

can be bnoken
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ble: . Scicntiti letthat

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Do background
Adyustnv
recarch

Specily requirements

onstruct a
huhesis

Test with an
yNrent
asasas avss** *******

speriental
data becomes
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and chuose solutuon

Develop and
prototype solution Based on results
and data, make
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ackground
Ture working" design changes.
research for
protolype, lest
hew/future Test solution
again, and revvew
Trutiohax project. Ask
newodats
Prcntr Cxersly new question.
chei aii sAps and lorm new
hypthesis, Solution mects Solution meets
Analyze data and experiment requirements requirements
draw conclustons again! partially or not at all
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Resuks alugn Resulis align partially Communicate

ARZh or results
hpocess noxat all wih
hypothesis ***********

18.
Ilustrate the role of engineers in the field of Biology. [MODEL QUESTION]
Lomunxate results Answer:
may not be a typical subject in the traditional engineering disciplines (i.c., civil,
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Ogy
rical, r mechanical), however, it is a fundamental component of disciplines such as
rems engineering. Bio systems engineering emphasizes the application of
systems (1.e., systems that include plants,
Cering principles to biologically-based biosystems engineering program is designed to
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hunmans). A
piv icroorganisms, or principles of engineering and to introduce
knowledge of the fundamental
bioldents
ological concepts to enable' these engineers to successfully interact with relevant
involving biological systems.
OCSSionals when solving engineering problems
Follov engineers can contribute:
. i
are the ways where
between biological and
electronic substrates:
Life's Matrix draws 'analogies b1ological concepts and
Ine
nlormation proces and control elements. organizational
BIO-10 On process, transport, units of lite, DioloBIcai components, and
nCiples include fundamental
nclude fundt
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POPULAR PUBLICATIONS parts. Rele ance 6. uan Genome jectfocuses on
waler manu facturing enabling
BIOLOGY
ngeable DNA to inloralic echnology
ot
ea
ereate librarncs engimeerng (AU:),
chcmical engineerin
sve ws. Aplicaion
and in
ques as
uques
advancem
wellents in compu
nputing,

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ucrarhy to be able to databae as well
sublisciplinas of
bivmatical
(t:tE) ai undustrial and
uisition, analysis, visuala
uali/ation
ases and as novel computatioa
elevtrival cnginern: and managementcomputational imethod
neringcomputer sciene (CS) methods
loicaliconcepts and priiciples include Molecular of biological intormatiofor The
biolo
the
nemE
engineering (ISE. chniqucs for cloning. DNA SCquencing. biology and genetic
engineering
uses tnc central dogma cnts..
Microarray appiicalions DNA amplification.
lntonnation Theory experime and hybridization
Biological Cireuits unt Bisogicalenporation of biomolecules nd DNA based tin linite ering subdisciplines
sub
for personalized
ot biomedical engineering medicine. Relevance to

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biological intorativn thevry aat the
logic. The biOlogical concepls
and princinl
ples eg computer science (CS), (BME). chemical engineering
state machine to ovintuct sirnple puting to computing Systems.
Process electrical engineering
(EE). mechanical
lite ani the netaphor f (ME) and imaterial science. engineering
ilude tundumental units of tor smooth intormatton TlOw,
Application of
transeription and translutiw: and nulation Kelevance to engineerin
ering
computational paradigms.
nucleic acid hybridizaivn tir ew 19. What are the similanties between camera and eyes?
(BNIE), cheimical engineering (Cheme [MODEL QUESTION]
subdisciplines of bivmaticai engimering Ansuer:
engineering (EE) and material scicnce. Ta beiter understand the answer to this question. let's first
Computer Science (CSi elsetrical have a quick comparison of
warious similarities and ditferences found in the working of the human eye and a photo
circuits.
3. Signal Transduction ss Cellular sinaling pathways that resemble electronic
caniera.
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Proteins and the prvtein kinase cascade act as amplifiers or switches. The biological
processes and structures needed Image focusing: Human and camera lenses both focus an inverted image onto light-
COncepts and primciples include an understanding of the
sensitive surface. In the case of a camera, it's focused onto film or a sensor chip. In Our
in converting chemical signals trom cell surface to the elicit appropriate cellular response
eyes. t* ight-sensitive surface is the retina on the inside of our eyeball.
at the molecular and protein levei. Relevance to engineering subdisciplines of biomedical light entering. On a
engineering (BME). computer seience (CS). and electrical engineering (EE). Light adjustment: Both the eye and a camera can adjust quantity of
in our eye. it's done
camera. it's done with the aperture control built into our lens. whilst
4. Control Systems and Feadback Control reveals that control loops are ubiquitous and by haying a larger or smaller iris.
can be tound trom irarseriptiona! (bacterial example) and physiological control [MODEL QUESTION]
(antagonistic hormones) to bioregulation. An întroductory description of 20. Describe our eye as a camera.
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theoretical
madeling. simulations. and bifurcasion diagrams to inform and guide Answer:
and predietions. The bioogical concepts and principles experimental design
include regulatory elements and
feedback control for cell cycle regulation. blood
sugar regulation, and environmental
rutrient sensing. Reulatory control points for
DNA synthesis and understanding
transport and movement of macromolecules Cilliary
across barriers Relevance to
subdisciplines of biomedical engineering engineering muscle
(BME), chemical engineering (ChemE),
computer science (CS electical engineering (EE),
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(EnvimE, industrial and systems engineering environmental engineerng

(ISE) and material
science.
5. Sensors and Detectors Optica
conveys elements
sy stems as welt as our of communication circuits PUp nerve
immune system using in bacteria
biological concepts and principles computer security
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includc Biofilms: systems analogy.

molecular level and novel quorum sensing characteristics Lens
applications to prevent
of immune system to provide
specificity. memory,
and disrupt biofilm a
forination. Feau
Regulation and meraction Cornea
at ihe molecular diversity and self-nonself recogni
Relevance to engneering subdisciplines level as well rs
as the physiological perspec
engineering hemE), computer of biomedical
ineering (EnvimE), science (CS), electrical engincering (1BME).
mechanical engineeringg enginecring che
(ME) and material (EE). environental
science.

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ddition lo straight-up light sensitivit
POPULARPUBLICATIONS ln range of the human eye (which OLOGY
aa lens. Together with
leIS, Together dy 1atnic isabs we'll get
element of
ght or in he brightest of sunlight. stonich backk to
com b toiin
the front lens clcnents. The rnea
ornea behaves much like eye's loclising i1stonishingn.Sunlighy just
ing: A human a minu the

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they are the absolutely sunlight, can see
the iris,
which is behind Urougn ne pupil, the round ects i

Tens.Widely diverging rays of light and bends them ess

m0onles night-and yet, we are ahleto between the
Ae's
ot thhe coloured iris.
which, when
ona to see under
two
U0.000,000 times moreextremes is
pening n the central portion aperture of a canera.
The iris IS a muscle
contro
both circumstances. light than
*ur Iris and pupil act like the portion of the lens. alloS adjustable ol 23, What
is Shutter speed of our eye?
central
Contracted. covers all but a small the eye can work veil in a wide range Answer:
eye so that MODEL QUESTION]
yuantity of light entering the
ne

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very brnght light.
Vhere Our comparison gets Complicated
of Viewing conditions, trom dinn to Is when we mix
. Finally. our Retina is the sensory layer that
lines the very dack Or our
eyes. It acts
camcra. he retna has numerous
I
like-for-like parison betiween the
ertures' and IS0
compare apertures ISO (which
(which
human eye
in shutter speed.
and a camera,
In order to
o
a
very much like the innaging sensor ehip in a digital is the most interesting we can quite Casiuy
pnotoreceptor nerve cells that help change the light rays into electrical npulses and
or speeds makes T compicatea, because exercise. in my opinion).
15tt
a camera
Send them through the optie nerve to the brain wlhere an image (or what
we see) is it t0. In fact, there are exaimples plhotos can stay open for as
long as ve
of taken with a 6-month
inally received and perceived. Because of this reception and perception function, ething which the human eye can obviously shutter opening.
not match.
retina is. perhaps. the most important component of our eyes. AS With the camera, if nloring what the shutter speed of a human eve is actually
the "tilm" is bad in the eye ti.e. the retina), no matter how good rest of the eye is, we surprisingly complicated. but
let look to animauon Ior a start: it you have ever seen
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will not get a good quality image or picture. any simple aninmation. you wil
have noticed'that il you don t get enough frames per second, things can look *stuttery".
If
21. What is ISO and why is it important? vou were to see a footbail Lame aa lips, for example. you would essentially
[MODEL QUESTION be sceing a
Answer: series ofI photo per second (at a maxumum of I second shutter speed). Obviously, that's
ISO is the number signify ing the light sensitivity not going to do any good, and the human eye has a 'shutter speed' of faster than that. To
of an imaging sensoi measured in.
numbers (ike 100. 200. 400, 800 etc). Sometimes, explore this question in further depth. I highly recommend the "How many frames per
this number is also known as 'an "ISO
number". or. more commonly, the "film speed".
Historically, the lower the ISO
number, second can the human eye see article over at 100fps.com. Despite the nanme of the site,
the lower the sensitivity of the film
and the finer the grain in the their conclusion is that they don't really know, because it depends on how you mcasure
taking. This has translated pictures or shots you are
pretty well into digital photography, the results.
higher sensitivity. but at the too: Higher ISO gives you
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cost of a larger amount of digital For low light photography. however, we don't need to know the minimum shuter speed of
ISO is the indication noise.
of how sensitive a film is to light.
the human eye, but the maximum. Obviously, we can sit perfectly still and stare at forest
This means that the a
setting. the more sensitive higher the ISO
the camera sensor is to light. anything. even though
with ISO 400 settings. you Accordingly, if you take a in the pitch dark for halfan hour. but we might not be able to "see
only need 1/4 of the light picture
we, in theory, have had a half-hour exposure. At the saime time, a camera might be able
with ISO 100 camera that will be needed to
settings. to take a picture it might not). When it comes to our own cyes.
it

22. Find out the ISO esolve something in that half hour (buta "shutter speed as such-our cyes sce with an
of the human eye. OCcomes less meaningful to speak of
Answer: is continuous process. In other words. our eyes will
[MODEL QUESTION CAponential decay, and our vision a
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The real issue with them into a more meaningtul image,

the human eye is that, multiple.'exposures', and our brain will combine
have any definite ISO unlike film and nC taking a inuiti-exposure tiDR
photograplh with our
levels. However, our camera sensors, you might do when you are
to ambient light levels eyes do have our eyes do not ke
a
However, the human even under the most severe lighting great ability to naturally adjust camera.
sensitivity. After eye has a mighty trick conditions.
up its sleeve: cameras, versus the human eye?
rhodopsin in our about 15 seconds in lower
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it can modify its talking about

light, our own lignt *Vnat is the ISO when we are [MODEL QUESTION]
sensitive. In fact, retina. Over the next half bodies increase
hour in low the leveli
night than during the
studies have
day.
shown that our light, our eyes
eyes are around get more an mo o Answer: it becomes
kges m dright light, and now
It should also LOvd at resonving and
be oled 600 times more
sensitive at he human eye is extremely our ees aren tmisiirng every
in existence. Every umethat the human eye not because (Just think
we change is like the
greatest, quickest gless to speak of 'noise' filters ou any" prools our eyes encouterone in each
everything else to compensate- where
nere we're , simply spotS you have -
we're looking
looking, our automatic camei but because our brain out ne vo tDin never
ensure that our eyesight is as focus,
gooditcan s, oynamic range eye (and retina) is changin nOW our brain is
constantly filtering
one
wn tne other. If you have
eve ana iOONInEastonishing).
be are all constantly eye are closing
even if vou it S rather
adjusting to give it a Shot,
BIO-14 CNperienced our blind spot - BIO-15
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om a brighr BIOLOGICAL
thu the n n [ilnn natS
. argument. la's siy that's the lmest-lSO ISO of our eyes is 25,
Currenly LASSIFICATIC
So. tor the sike of
25. Vhy 25 Bause
est
thelonics
ne nAxNUm ISOat

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n day. is IS) yuality anmnl. lt
n the least grain and the highest
seustive in the dark. tht imc:uns it
lI yu choOSe ISO 10D0 our Chapter at a Glance
ol0 times m or so. cvo
IS) 15,00 re conmparing
humnCsarteye Houhi lund
snewhe* annd
is equally
tair, consnsering N we
maximum cal classification or
Biological plan and
of plants
use SO fir the human
eve (whish
days stat
ial do
tu Our aninals was first
digital St.Rs these orphological characterS. Linnaeus
simple morphologic
proposed by Aristotle
cameras, annd mst later on the basis o
to digital plantae and Animalia. whittaker proposed an classified

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all living orgánisms
can take photos.at intotwo kingaoms
(SO is arvund bO,00. (Like the Nikon DsS) elaborate five
highest-180 cameras behind ista, Fungi. Plantae and Animalia. The main kingdom classi fication - Monera.
When we consiiker that the technology Is starting to lag criteria of the five kingdom
that our built-in llstructure, classification were
up to IsO l02.000. it homes elear bodY organisation, mode
of nutrition and reproduction. and
are covking up: relationships. phylogenet
what the camera manufacturrs
[MODEL QUESTION]
bird and air craft.
25. Write the difference between in the five kingdom classilication, bacteria are included in Kingdom Monera. Bacteria are
Answer Air Craft osmopolitan in distribution. Ihese organisms show the most extensive metabolic diversily.
Bird airplanes use a propeller to tly_
Bacteria may be autotrophic or heterotrophic in their mode of nutrition. Kingdom Protista includes
Birds tlap therr w ings ta tiy- all single-celled eukaryotes such as Chrysophytes. Dinoflagellates. Euglenoids, Slime-moulds and
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Airplanes use cables. and electrical wires to
birds twist their wings to maneuver maneuver Protozoans. Protists have defined nucleus and other membrane bound organelles. They reproduce
airplanes wings only gives lift aftcr engines, both asexually and sexually. Members of Kingdom Fungi show a great diversity in structures and
Birds w ings provkdes thrust and hft
or gravity would provide electricity habitat. Most fungi are saprophytic in their mode of nutrition. They show asexual and sexual
reproduction. Phycomycetes. Ascomycetes, Basidiomycetes and Deuteromycetes are the four
classes under this kingdom. The plantae includes all eukaryotic chlorophyll-containing organisms.
in this group. The
Algae, bryophytes, pteridophytes, gymnosperms and angiosperms are included
and sporophytic generations.
life cycle of plants exhibit alternation of generations -gametophytic
organisms lacking a cell wall are included in the
The heterotrophic eukaryotic. multicellular
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organisms is holozoic. They reproduce mostly

Kingdom Animalia. The mode of nutrition of these
organisms like viruses and viroids as well as the lichens are
by the sexual mode. Some acellular
not included in the five kingdom system of classification.

Multiple Choice Type Questions

QUESTIONJ
. classification was proposed by- [MODEL
rinomial nomenclature of
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b) Huxley and Stricklandt

a) Linneaus. d) Theophrastus
c) John-Ray
Answer: (b)
foflowing language
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2. M names are drawn from the [MODEL QUESTION]

Most of the botanical
c) Latin d) Spanish
b) Greek
a) German
Answer: (c)
MODEL QUESTION]
. Evolutionary classification is caled- b) Natural system
a) Artificial system d) None of the above
C) Phylogenetic system

BIO-16 Answer: (c)

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groupsr [MODEL QUESTION] Ansver: (b)
than one BIOLOGY
in more Artifical classilication
. System classifies a
classitieation
plant b)
d) Phylegenetic
classitication 14. Which of the foll owingorganisms
) Practical

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ciassiticatren ever included
c) Natura Bactorla
a) in prot
Ansner: t)
b) Red algae
(MODEL QUESTION] nswer: (d) [MODEL QUESTION)
c) Slimemolds
.Author of bock "Fiera
British Indied b) J.D. Hookor d) Mosses
a) Father Santapauu d) G. Bentham 15. Among the following
following organisms
c) William Rouxburyh
point out a
completely non-parasitict
Answer: (e

6. Ringdonm monera compriseS

Auser:
.
ic
the-
a) Piants of econemic importänce
c) bldiryetc organisis

ACCoraing to Whittaker kingdem monera includes

a) Uniceliular euharyotes
c Siime meids & protoz0a
(MODEL QUESTION
b) All the plants studied in botany
d) Plants of Thallophyta group

(MODEL QUESTION]
b) Prokaryotes & akaryotes
d) Multicellular & eukaryotes
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16.
a) Soa
c) Tape worm
Answer: (a)
anemone

Embryophyta include:
a) Algae
Answer: (c)
b) Fungi
c) Bryophyta
b) Leech
[MODEL QUESTION].
d) Mosquito
form

[MODEL QUESTION]
d) All of these
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17. According to tour kingdom system of Copeland,
the fungi belong to kingdom
Answer: td
[MODEL QUESTION]
a) Protista b) Mychota c) ldycota
S. Kingdem ef unicsliuiar eukaryotes MODEL QUESTION] d) Plantae
a) Mener b) Protista c) Fungi d) Plantae Answer: (a)
Aaswer:
18. Which animal is "Non-chordate-protochordata" [MODEL QUESTION]
9. Engler and Franti created metachlarnydae
to include-[MODEL a) Herdamania b) Balanoglossus
QUESTION]
a) Polypetalcus dicots b) Gamopetalous dicots c) Branchiostoma d) Botryllus
c) Gamapetalcus mOnccots
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d) Gymnos perm Answer: (6)

Answer:(O:
19. Sometimes parasites themselves are parasitised by other organism, such
10. In two kingcam system cf [MODEL QUESTION}1
classification Euglena is included in- parasites known as
a) Symbionts b) Endoparasites
a) Animalia [MODEL QUESTION] d) Hyperpa rasites
c) Bcth the atove b) Plantae c) Ectoparasites
Answer: (C d) Protista Answer: (d)
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11. Whittaker placed organization, animals are grouped

as
prokaryotes and eukaryotes .On the basis of body [MODEL QUESTION]
a) Protistaa in
Answer: (d) b) Protozoa
c)
[MODEL QUESTION] b) Protozoa and parazoa
Plantae d) Monera a) Metazoa and eumetazoa d) Protozoa and metazoan
Parazoa and metazoa
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12. According to
four kingdom Answer: (d)
system of Copeland,
the fungi belong to
a) Protistaa kingdon vertebrates without exception is QUESTION]
Answer: (2) b) Mychota [MODEL QUESTION] 41. A common characteristic of al [MODEL
c)Mycota appendage
d) Plantac two pairs of functional
13. According to copeland a)
possession ofwell-developed skull
a) Monera the"Red algae" esonce of trunk and tail
6) Protista bolongs to Th into ad, neck,
[MODEL QUESTIONJ] c) The
c) division of body ith an exoSkeleton
c) Plantao0
d) Animalia d) Their body is covorco
Answer:
BIO-18 (b)
BIO-19
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Answer 1ype Questions Answer: BIOLOGY

LShort & Long

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It is a taXOnomic category
MODEL QUESTION] of the highest [MODEL QUESTION]
certain lundamental haracteristic rank.
Classification? grouping together
1. What is biological
Answer: scientitic study of arranging
organisms into groun
group in
. ne adopted by
scheme by many
man Common: in
(Animalia). plants (Plantae). biologists. separate kingdoms
all forms of life having
the five-kingdom
classification
BOlogical Classitication is thesimilarities and dissimilarities and placing the funi (Fung are assigned
Subgroup on the husis of their protozoaand
eukaryotic
8. What are the diTerent types algae.

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hierarchy vf categories
is to organise the vast numder
of known plantets of the classification?
purpse vf biological classitication Answer:
he caregories that cvuld be named, remenbered
and studied. There are three ditferent
types
[MODEL QUESTION]
nto of the biological
[MODEL QUESTIONI a) Artificial System of Classification classification:
2. What are the objectives of biological classification? b) Natural System of Classification
Answer: c) Phylogenetic System of Classification
Objectives of Classification
To identity and desrie all the possible types of species. 9. State the Artificial System of Classification.
To arrange the spacies in various categories on the basis of. their similarities and
Answer: [MODEL QUESTION]
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dissimilaritis.
Artificial System of Classification
To evolve a truly natural or phylogenetic system which should indicate origin and
It is a system of classilicati0n which
evolution of the species. uses one or two morphological
character tor
Helping in easy identification otf organisms. grouping of organisims. Some artificial, system
have used habit and habitat for this
purpose. Aristotle (c 350 BC) divided animals into
two categories. enaima (with red
3. Which branch of biology teaches the classification? [MODEL QUESTION] blood) and anaima (without red blood). Aristotle also classified animals on
the basis of
Answer: their habitat- aquatic (e.g, fish, whale). terrestrial (e.g, reptiles, cattle) and aerial (e.g
One branch of biolog. called taxonomy, focuses on the birds, bat). Pliny the Elder (23-79 A.D.) used artificial system of classification for both,
Taxonomy is the study of relationships
clawification of living things.
between livi things and, the formal plants and animals dividing them into land. air and water. Pliny distinguished animals
classification of organisms into groups based
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upon those
h hesized relationships. into flight band nonflight ones. Flight animals included bats, birds and insects.
4. Who is father of the biological classification?
[MODEL QUESTION 10. State the Natural System of Classification. [MODEL QUESTION]
Answer:
Carl Linnaeus. Carl Linnaeus. Answer:
also known as Carl von a system of classification which takes into consideration comparable study of
a
often called the Father Linné or Carolus Linnaeus, IS tis
of Taxonomy. His system for characters so as to bring out nature similarities and dissimilarities and hence
organisns is still in wide use naming. ranking, and classitying number of
today (with many changes) which are
ature relationship among the organisms. Ihe system employs those characterscharacters
anatomical
relatively constant. They include morphological characters.
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5. What is taxon?
or development, rèproduction.
Answer [MODEL QUESTION] cytological characters. physiology ontogeny characteristics are
taxonomy. etc. the
In biology. a taxon
(pural taxa: back-formation cytochenmistry and biochemistry. experiumental comparable
more populations or an number or similarities in a group and
orpanismor organisms
from taxonomy)
is a group of oneO helpful in bringing out maximum example, mammals are characterised by
seen by taxonomists differences with other group of organismS. for
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6. What is Species ? to form a unit.

birds posNesS wngs. Ieathers,
pneumatic bones. ovipary, 4-
nmammae,
the presence of
Answer:
In biology. a species [MODEL QUESTION] chambered. They are coldblooded
is
an organism, as welt as theebasic unit of classification Classification. [MODEL QUESTION]
a Phylogenetic System of
group of organisms
can produce
unit biodiversity.
in which any A species is
and a taxonomic
ran 1. State the
Answer:
fertile ofispring. mdividuals often defined as the Clasification
of the appropriate lar ylogenetic System of called phylogenetic
typicany sexual reproduction. sexes or mating evolutioary relationship of organims is
tyP based
Classification on from darwin's book- on.
It is dcd on tne Evolutionary concept
Sy'stem of' classification.
BIO-20 BIO-21
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The
preservation or lavoured Si.Characters
among the organisms
BIOLOGY
natural selection. ms. First No.
Monera
species by means of relationshps Protista
n of Zoologists br

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reflects the true (1887-99). believe 7 Motility Bacterial
the struggle for life (1859). It Prantl Cilia. Fungi
by Engler and
Plantac
relationsnip, their natural
"al flagella, Animalia
system was proposed agella| Cilia, flagella

Ce
e
Stmilarity in structure
represents close
evolutionary
phylogenetic classification.
and
gliding amoeboid
or contractile OF in
('ilia
some.| lagella andC Cilia
in flagella.
and
represents evolutionary non-motile
hone in most lower
ication [MODEL QUESTION]
fibrils
theof forms
forms,| contractile
ahsent
12. What is five kingdom classificatiot in fibrils

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Imost of the|
Mode oAutoropnicPhotosynthesis
Answer: Heterotrophi Autotrophie
Five Kingdom Classificution an American nutrition chemosynthet
classification, R.H. Whittaker (1969), |and
ic and photo-|heterotrophic
Heterotrop"
In order to develop phylogenetic As the viruses are on the
by
into five kingdoms. Saprophytic photosynthe ingestion
axonomist. divided all the organisms synthetic,
have been letft out. Whittaker has used five and parasilic sis
border line of living and nonliving, they heterotrophic
absorptive
criteria for delimiting the different kingdoms. (saprophytic
) Complenity of cell structure. prokaryotic and eukaryotic. and parasitic)
organization, unicellular and multicellular.
2) Complexity of body structure or structural
3) Mode of nutrition which is divergent in multicellular kingdoms- photoautotrophy
in ReproductiConjugation Syngamy and | Fertilization | Fertilization |
Fertilization
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means transduction meiosis, conjuga and meiosis,
plantae. absorptive heterotrophy in fungi and ingestive heterotropy in animalia. on/ | and meiosisand meios1s
Photoautotrophy totrophic nutrition is also called holophytic nutrition while ingestive of genetic | transtormatio Lion or none dikaryosis or
as holozoic nutrition. Absorptive heterotroPY recombinati n or none none
heterotrophy is knovwn
is saprobiotic (=saprophytic ) nutrition. on
4) Ecological life stye like producers (plantae), decomposers (fungi) and consumers
10 Nervous Absent Primitive 1or Absent Absent Present.
system Conduction often
animalia). complex
stimuli
5) Phylogenetic relationships.
14. What is 'Three domains of life'? Why it is called Six Kingdom Classification?
13. Describe the Characteristics of five kingdom. [MODEL QUESTION] [MODEL QUESTION)
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Answer:
Characteristics of five kingdom Answer:
Three Domains of Life
biological classification which was introduced by
Carl
NoCharacters Monera Protista Fungi The three- domain system is a
Plantae Animalia of microbiology, university of llinois,
Cell type prokaryotic Eukaryotic Eukaryotic - Woese, a professor in the department cellular life forms into archaea,
Eukaryotic Eukaryotic 1990 that divides
Urbana- Champaign in
Cell wall bacteria and eukarya domains.
Non Present in some Present (non | into two groups, originally
called eubacteria
cellulosic (various types) cellulosic) Present absent the separation of prokaryotes their tfundamental
t emphasizes archaebacteria (now archaea) because of
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polysaccharid (cellulose) bacteria) and with

(now
that each of the two
arose separately from an ancestor
amino ditferences, Woese argucd called a progenote.
acid) machinery, oftern
system
ChloroplastAbsent poorly developed genetic on the traditional tive- kingdom
Present in some system is loosey Dasea eukaryotic kingdoms
Absent |
Present n fact the three-domain leaving the remaining
Abseent into two "domains,
Dut divides the monera
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Mitochondr ADsent Kingdom Classification.

Present in,somePresent it is called Six
ia Present n the third domain. So
Present [MODEL QUESTION]
Nuclear Absent classification.
Ptesert domain
6. Describe the three
membrane Present
Present Present
Tissue or Absent AUSen Answer:.
nave a monolayer core of
lipids in the
multicellula n

rity
resent
limited
but Present in all | Present n )Archaea domain prokaryotic organisis IcINA. It contains
a single kingdom
fornis domain contains n neir 10
all forms distinct niucieotides
BI0-22 cell membrane and BIO-23
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gliding. non-motile BIOLOGY
Flagella, if r
extreme cnvironiments, present,
Ent, are
by beating
Kingdom archacbacteria prokaryotes which live in composed many,of simple flagella or y

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early Moneran cells are hey arenot enclosed of intertwined cna
m cotain metlhane. by any membrane a
dioxide into microscopic
For Evumple: Most organisins (( to few microns' and grow the tip
hydnogen and earbon bear a rigid cell a
nogens:livemetabolize degrees Celsius).
Reproduction is
primarly asexual by
wall (Peptidogl
in lengh).
yean).
temperatures (upto l0
in salt. I
(6) Halophiles: Mitotic apparatus binary fission'
hermo0acidophiles: line in acid high or
is not formed
during cell division. budding.

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(2) Bacteria domain: coverea Cen organelles but do 18. How bacteria can be classified
which lack membrane on the basis of
contains prokaryotes their shape?
ne domain micro chambers for separating various
aciviues. here iS a single
Answer: [MODEL QUESTION]
nve a sort of
.
kingdom. Cocci: hey are oval or spherical in
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shape. They are called micrococcus

singly as in Micrococcus, diplococcus when occur
domain contains eukaryotic organisms which
originated by when found in pairs as
() Eukarya domain. The pneumoniae, tetracoccus in fours, streptococcus in Diplococcus
it has four
endosymbiotic assaciation between some archaebacteria and eubacieria. Streptecoccus lactis staphylococcus when occurring
when found in chains as in
kingdoms- protista. fungi. plantae and animalia. in grape like clusters as in
Staplhylococcus aureus and Sarcine, when found in
cubical packets of or 64, as in
[MODEL QUESTION] Sarcina. 8
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16. Describe the Kingdom Monera.
Bacilli: They are rod-shaped bacteria with or without flagella.
Answer: They may occur ingly
() Bacteria are the sole members of the Kingdom Monera
(bacillus), in pairs (diplobacillus) or in chain (streptobacillus).
2) Bacteria are grouped under four categories based on their shape: the spherical Coccus, Vibrios: These are small and 'comma or kidney' like. They have a flagellum at oine
the rod shaped Bacillus, the comma-shaped Vibrium and the spiral Spirillum. end and are motile, vibrio bacteria has curve in its cell e.g, Vibrio cholerae.
(5) Compared to many' other organisms, bacteria as a group show the most Spirillum: They are spiral or coiled like a corkscrew. The spirillar forms are usually
extensive
metabolic diversity. rigid and bear two or more lagella at one or both the ends e.g., Spirilum,
(4) They may be plhotosynthetic autotrophic or chemosynthetic Spirochactes etc.
autotrophic. Some of the
bacteria are autotrophic. i.e. they synthesise their own food Filament: The body of bacterium is filamentous like a fungal mycelia. The filaments
from inorganic substrates.
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(5) The vast majornity of bacteria are heterotrophs, are very small e.g.. Beggiota, Thiothrix etc.
i.e.; they do not synthesise
food but depend on other organisms or their own
on dead organic matter for food. Stalked: The body of bacterium possesses a stalk e.g., Caulobacter.
.Budded: The body of bacterium is swollen at places e.g., Rhodomicrobium
17. Describe the characteristic
feature of Monera.
Answer: [MODEL QUESTION] MODEL QUESTION]
19. Describe the structure of bacteria?
Characteristics of Monera
Monera(NMonos single) Answer:
includes prokaryotes
Ahey are typically unicellular organisms (but and shows the following Structurc of Bacteria a slimy capsule is present outside the cell
characters:
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The genetic material is one yroup is () In a large number of bacteria,

Capsule:
naked circular DNA, mycelial). nitrogenous substances (amino acids) are
Ribosomes and simple chromatophores not enclosed by wall. composed of polysaccharides and the
It is
capsule. The bacteria,
are the only subcellular
nuclear envelop
present in addition. This slime layer becomes thick, called,
cytoplasm. also capsule 'is usually
organelles in tn capsule, are' called capsulaed or virulent bacteria. The
The ribosomes are 70S. Wnich form a
15acius, anihracis, DiplococCus
pneumoniae,
in parasitie forms eg.
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Mitochondria. plastids. TOund

centrosome, erc., are golgi apparatus, lysosomes, endoplasmic Mycobacterium tubereulosis. a strong. rigid cell wall. Therefore, they
lacking reticuiul cells .are covered by
Sap vacuoles do not occur. (2) Cell wall: All bacterial Capsure cewat is present. are It 'is made up of
Instead, gas vacuole linmer to the
The predominant may be are classified under plants. o Dacteria there two important
mode o
photosynthetic (holophytic) nurition is absorptive present.. ine celt wai
polysaccharides, proteins and lipids.in(N-ucetyigucOsamine
and chemosynthetic.
and N-acetyl muramic acid)
but some groups are NAG and NAM
Olaminopimelic acid are also found.
Sugar derivatives i.e., acid and
and besides L or D
alanine, D-glutamiC

BI0-24 BIO-25
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in the altachment of the
membrane: Each
harteria! cell
sSp Plasna which DNA of one
bacterial
cells. Some:
cell passes into
BIOLOGY
cell wall. t sex pili
1asma inemal tu the the other acts as conjugation
canals

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througn
atedand just
differentially rselatNC 20. What is Staining of Bacteria?
nin, elastie compvsed of iing
Ameun
membrane. It is amuUnts o Answer:
neadie
phospholipids. prvteins and svne oy
ctaarateriseal
Cell Wall Capsule Staining of Bacteria [MODEL QUESTION]
stenv!s. it is
saccharides but lacks ground substane
pssessin rspiratr cnzyinies. fluid or semitluid Gram Positive
comples aqucDUs

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is a
Ctoplasm: The eytoplasn
crtvhyurates soluble pteins. Fixation
Gram Negative
matia) cUnsisting ot lipids. nineral. salts
mes cUenzymes, vitanmins
Cy vrzanis matter is in the
collodat
and rucleic acids. The or a
is granular due to presence Cytoplasm
SEate. the cytoplasn
Ribosomes in bacteria are Crystal violet
large number of ribsems.
polyribosome. Nlembranous
found in the form of
Orgareiles Sch as itrhondia. endoplasmic
are
buis hssomes and vacuoles
lodine treament
reticulum. oli
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the plasma
absent In some phRSY nthetic bacteria
are rich in bacteriochlorophylls
membrare gs ris to lange vesicular thylakoids which
and proteins. Decolorization
(5) Nucleoid: lt is also known as genophore. naked nucleus, incipient nucleus. There is
nuclear material DNA which is double helical and circular. It is surrounded Some
ypical protein (poiyamine) but not histone proteins. Histones (basic proteins) are
altogether absent it bacteria. This incipient nucleus or primitive nucleus is named as Counter stain
nucleoid or genoptore. safranin
(6) Plasmid: In addition to the normal DNA chromosomes many bacteria
(e.g., E.coli)
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have extra chromosoma genetic elements or DNA. These elements are

called plasmids.
Plasmids are sirall circuar double stranded DNA molecules.
The plasmid DNA (1) Simple staining: The coloration of bacteria by applying a single solution of stain to a
replicates independently maintaining independent
identity and may carry some important
genes. Plasmid terms was given by Lederberg
(1952). Some plasmids are integrating into fixed smear is termed s nple staining. The ells usually stain uniformly.
in 1884. It is
the bacteral DNA chrom.osome called
episomes. (2) Gram staining: This technique was introduced by Hans Christian Gram
(7) Flagella: These are fine. thread-like, a specific technique which is used to classify bacteria into two
groups Gram +ve and
protoplasmic appendages crystal violet. The
which extend through the cell
wall and the slime layer Gram -ve. The bacteria are stained with weakly alkaline solution of
flagellated bacterial cells. These of the percent iodine solution. This is followed
stained slide of bacteria is then treated with 0.5
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help in bacteria to swim

the liquid medium. Bacterial about in ethyl alcohol. The bacteria which retain the
flagella are the most primitive by washing with water or acetone or 95%
motile organs. Each is composed of all +ve. Ihose which become decolourised are called as
of a Single thin fibril as purple stain are called as Gram
the 9+2 fbrillar structure against
of eukaryotic cells. The Gram -ve.
composed entirely of flagellum is
ilagellin
(8) Pili or Fmbriae: Besidesprotein. Gram +ve Bacteria and Gram -ve Bacteria?
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present on bacienal cell flagella, some 21. What are the differences between [MODEL QUESTION]
surface. These
tiny or small hair-like outgrowtns
They measure are-called pili and
abou-2mm in length and
I1, 111, IV, V, VI,
are made up of pilin
prolc
VILand F types. 3-5mm in diameter.
all gram-ve bacteria I to F are called These are of 8 type>
anaiew gram sex pili. These
holding the bacteria to solo sgiaces.
ve bacteria.
Fimbriae take
are present in a ost
The function part in atlachment
of pili is not in motility but uey
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pifference between Bucteria
and BIOLOGY

-ve Baeteria Sl. Bacteria

nobacteria
and Gram

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Answer: tve Bacteria Gram-ve Bacteria The cells are comparatively
terences Between Gram smaller. Cyanobacteria
stain w The cellwall is 1-2
SI. Gram tve Bacteria di no rean the when yered. ne
cells are comparatively
No or purple| The bacteriaalconol. Plasmodemata
and pores The cell wall is four larger.
coloured bluce with absolure walls do not occur
washing with washed layered.
eain
ngram stain even
Outer meiuorane
ered. Outer
layered. me. They exhibit lesser
structural
in cell| They
are often present.
absolute alcohol or acetone. wall is two

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elaboration.
single layered.
Outer| The They
ne all is present. show higher degree
IS
morphological complexity as of|
membrane is absent. It is 8-12nm. well as
wall is 20-8Onm. Bacteria are structural elaboration.
The thickness of the OOtn autotrophic
20-30%. heterotrophic. and Cyanobacteria
contain chlorophyi
content of the wall is .

wall is quite low. | The lipid Autotrophic as found in eucaryotic autotrophs.

he lipid content of the bacteria'
possessCyanobacteria contain chlorophyll
ana comes contact
in bacteriochlorophyl. a s
The wall is wavy Photosynthesis anoxygenic. lound in eukaryotic autotrophs.
The wall is straight.
with plasimalemma oniy at a tew places. is
. erein or mucopeptude content is 70-|
It is 10-20/%.
Photoautotrophic bacteria do
phycobilins.
not
Photosynthetic is oxygenic.
contain| They possess accessory vater solubie
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S0% photosyntlhetic pigments known as
occur the basal
two| Four rings of swellings phycobilins.
in
Basal body of the flagellum has Flagella may be present.
body Flagella are absent.
rings of swellings. J. Carbohydrate reserve food
Mesosomes are more prominent. Mesosomes are less prominent. is glycogen. Carbolhydrate
reserve food is a
more susceptible to| They are more resistant to antibiIotics.
Special starch
The bacteria are
Known
antibiotics.
cyanophycean
Fewer pathogenic bacteria belong to| Most of the pathogenic bacteria are (Giram* Starch.
Gram 7ve group. Ve.
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Porins are absent. Porins or hydrophilic channels occur in| 23. Describe the kingdom Protista? [MODEL QUESTION]
outer membrane of cell wall. Answer:
12 Cell wall contains teichoic acids. Teichoic acids are absent. All Single-celled eukaryotes are placed under Protista, but the boundaries of this
kingdom are not well defined.
22. What is Cyanobacteria? How it is different
Answer:
from bacteria? [MODEL QUESTION] Members of Protista are primarily aquatic.
Cyanobacteria This kingdom forms a link with the others dealing with plants, animals and fungi.
and other
Being eukaryotes, the protistan cell body contains well defined nucleus
a
(Blue green algae, Cyanophyceae,
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Myxophyceae) membrane-bound organelles.

Cyanobacteria or blue green
-
algae are gram F) photosynthetic - Some
have flagella or cilia.
perform orygenic photosynthesis. prokaryotes wnic
.

process involving cell fusion and zygote

Photosynthetic pigments
include chlorophyll a, Protists reproduce asexually and sexually by,
Food is stored .in the carotenoids and phycobilins. formation.
form of cyanophycean Saprotrophic, parasitiC and symbionts. Sone
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granules. starch, lipid globules may be photosynthetic, holotrophic, +

Cyanobacteria evolyed and prottein It
nave mixotrophic nutrition (holotrophic saprobic).
more than 3 billion are collectively called phytoplankton.
They added oxygen,to years back. photosynthetic, floating protists termed zooplankton.
the atmosphere and
forms, including aerobic bacteria. paved the path Ihe free-floating, holozoic protozoans
are collectively
groups:
for evolution of aeroo he
*Unicellular protists have been broadly diyided in to three major
Diatoms, Euglenoids
Photosynthetic Protists: Example: Dinolagellales, Myxomycetes
(a) moulds or
Protists: Example: Slime
(b) Consumer L0olagelata, Sarcodina, Sporozoa, Ciliata
Protozoan Protists: Exampie:
(c) BIO-29
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POPULAR PUBLICATIONS Life cycle of . This is found in the
es of
different ype
[MODEL QUESTION mat BIOLOGY

cycle? What
are the
similar.
moulds of
protozoan
protists, diatoms
4. What is Life and tlhat milar phase The organism spends and acellular slime

TI
most of its
in one gecralion The gametes are life cycle
any given phase only in the 2nconditio
Answer: betueen called genetic meiosis). In (haploid) ition.
ence
Thes ofeventsgeneration constitute a lite eeic.
next succeeding in prvtists
The gametes tuse to Torm
that are produced
by meiosis
als
the
wo types of lite eyele are found
zygote that grows
to form the diploid
Showing Zygotic Meiosis: Ciametes individual.
(a) Life Cyele 25. What are the major groups of

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(n) Protists?
Answer: [MODEL QUESTION]
Major Groups of Protists
Chrysophytes
Sexual Reproduction
This group includes diatoms and golden
(oflspring produced algae (desmids).
AS meiosis)
They are found in fresh water as well
as in marine environments.
Repit They are microscopic and float passively in
(ettspring
rtid
tisis) ALture Fertilization
water currents (plankton).
In diatoms the cell walls form two thin overlapping
shells, which fit together as in a
Growth ygote Soap boxX.
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Mexss (n
2n) The wals are embedded with silica and thus the walls are
indestructibie.
HaploidN diatoms have. lett behind large amount of cell wall depositsin their habitat; Ihus, this
Diploid accumulation over billions of years is referred to as 'diatomaceous carth.
von stosch, Being gritty this soil is used in polishing, filtration of oils and syrups.
It occurs in some dinoflagellates (Example: ceralium, gVmnodinium:.
Diatoms are the chief producers' in the oceans
1973) and cellular slime moulds.
The zygote is 2n that divides by meiosis (also called zygotic meiosis) and
produces vegetative cells with In chronmosome number.
These cells divide repeatedly by mitosis and all the resulting daughter cells
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maintain the In number of chromosomes.

Sorne of the vegetative cells produce gametes.
When these gametes combine in fertilization, a zygote is formed and the life cycle
is completed.

(b) Life Cyele Showing Gametic Meiosis:

Dianoflagellates
organisms are mostly marine and photosynthetic.
These
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blue or red depending on the main pigments

hey appear yellow, green, brown,
present in their cells.
on the outer surface.
The cell wall has stiff cellulose plates in a
one lies longitudinally and the other transversely
Most of them have two Nagella;
Asevaal reproduction
Sexual reproduction
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ofsring produccd plates.

(offspring produced by Turrow between the wall
yartos.is (Exaniple: Gonyaulax) undergo such rapid
meiosis) Very often, red dianotlagelates appear red (red tides).
sea
e
Mature
Fertilization
multiplication that they make the
numbers may even Kill other marine
animals such as
Mitosis
Cen Toxins released by such large
(n)
fishes. formation of
1laploid througn cell aiVISion or by the
Meiosis Diploid Dinoflagellates reproduce asexUaiy
2 (2n)
Z00Spores and cysts.
BIO-30 BIO-31
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division, ceni BIOLOGY
During cell microtubules.
fhom
posterivr end. eytoplkasnmie ,

TI
he cell division starts
spindle is
neplaced by chronatiuls. The Du
nuclear
rurs of
spindle are not secn. the
chromosomes break up into
Durin the
mtosis,
and nuclevlus
elops
persists during,
divisiot.
is isogamous
or anisoganS.
v ,

occurs. it where the two

amoedod gamcles fusa
se to
Sexual reproductionby conjugation canal
conjugate a

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Cells (iyninodinium etc.) or
form a diploid zygote. (Example: Ceratum.
Lie cy cle involves zygotic meiosis Slime Moulds
(Example: Notiluca).
gametic meiosis . Slim moulds are saprophytic protists.
The body moves along decaying twigs and leaves
, Starh inclusons engulfing onanic materia.
Under suitable conditions, they form an aggregation
l inelusSAOINS called asmodium which may
grow and spread over several feet.
During unfavourable conditions, the plasmodium differentiaes and forms fruiting
Cingulum
bodies bearing spores at their tips. The spores possess true walls. The spores are
AK
Transverse Undulpodium dispersed by air currents.
Nucleus
They are extremely resistant and survive for many yearš even under adverse
conditions.

26. What is Protozoa? What are the different types of Protozoas? Describe them.
ChrvTItAptare Sulcus [AODEL QUESTION
Undulipodium Answer:
(lagellum Protozoans
All protozoans are heterotrophs and live as predators or parasites. Tey are believed to be
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Euglenoids
Majority of them are fresh water organisms found in primitive relatives.of animals.
Instead of a cell wall. they have a protein rich layer stagnant water. There are four major groups of protozoan
body tlexible. called pellicle which makes their
They have two tlagella. a
short and a long one. The Group 1. Flagellated Protozoans
at a swelliny called two flagella join with each other Characters:
paratlagellar body. An orange
located atthe base of red coloured eye-spot
tlagellum attached to the
membrane of reservoir
or:stigma i
paraflagellar body. at the levelO
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Both paralagellar
body; and eye spot act
organism towards as photoreceptors
the optimum light. and direct the
Thoughtheyare photosy
nthetic in the presence
they behave like heteroirophs of sunlight, when deprived for locomotion.
the pigmenis ofeugenoids by predating on other smaller of sunlign ( They possess flagella
living aquatics, parasites,
Commensals or symbiont.
are identical to organisms. Interesting (1) They may be free occasionally multinucleate.
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Euglena. They conmain

red pigment
those present in
higher Zooflagellates are generally uninucleate,
Nutrition is holophytic astaxanthin.
(photoautotrophic).
plants. ExainnP ) covered by a firm pellicle.
(e.g. Peranema). Even saprobic (e.g.. v The body isholozoic, saproboic and parasitic
holophytic forms Rhabdomonas)
outside medium.
can pick up or zoic Nutrition reproduction
is
is by binary tission.
Such a mode organic compounds ho the ) Asexual
Euglena
mixotrophic,a
is connecting link nutritionis
when light
called
between animals mixotrophic. fron Exanmples: nce pars or sieeping sicknes. It was sleen
first
absorbing food from is available t and plants.
is photosynthetic, Nutrition in Euglena Trypanosome gambiense: 1901. Fruce discovered
that the paraite e of eping
surrounding water. in darkness it observed by Forde in It causes Gambian sleepikg sickness. The
is sapropiy transmitted by tse-tSe Tiy.
BIO-32 sickness is' BIO-33
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in
iwestern and central
stern anI BIOLOGY

TI
trypanosomiasIs, Is foUnd Plasimodium, monocystis, cimeria
Gambain
Scase. also cailel disease is also
parts of Africa Rhodesan siekiess, The Group 4. Ciliated Protozoans
pansoma rhxlesiense: t causesThe parisile is transtnitea by the bites Characters:
trypanosomiasis. is pre-
Initia parasite Ciliates are protozoan protists which
Caled Rhodesiar palpalis and glossina moslas).
flud.
Sese tly nan but later en it enters the cerebospnal
(glossia of the life cycle. develop a
(alo

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number of cilia
tne tioNof American panOSomiasis so during a part or wno
npanosome cruzi: It causes South
disease are Tever, diarrhe
of the
usease). The sv mptoms
called Chagas
lymphnd glands.
anaemia and enlryen:ent ot

Group 2. Amoebid Przoans

Pseudopodium
Ectoplasm
Endoplasm (ii) Cilia are used tor locomotion and driving
food.
(ii) There is a high degree of morphological and physiological
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Cell membranc specialization.
(iv) Most ciliates are free living individuals in fresh
and marine waters. A few are
parasitic.
(v) The body is covered by a pellicle.
(vi) Nutrition is holozoic except in the parasitic forms.
Fod vacae. Contractile (vii) there are definite regions for ingestion and egestion. The region of ingestion consists
acuole of an oral groove, cytostome (mouth) and gullet.
Characters Examples:
() They develop pseuepodia which are temporary protoplasmic outgrowths. They are of Paramecium, vorticella, opalina, balantidium.
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four types- lobopodiai broad and blunt). filppodia (slender,

unsupported, independent), 27. What are the characteristic features Fungi? IMODEL QUESTION]
apodia (slerder withirial support) and reticulopodia (slender, reticulate).
(ii) Pseudopodia are ved for locomotion and engulfing food Answer:
articles.
(i) Sarcodines are sly free living. found in fresh water, sea Characteristics of Fungi.
Only a few are parasiic. water and on damp soi. Thallus Organization
(iv) The body may b Covered w
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he plant body of true fungi (Eumycota). the plant body is a thallus.

ith plasmalemma or a shell. non-mycelial forms are unicellular;:
Eramples: Amoebepetomyxa, entamoeba, Itmay be non-mycelial or mycelial. The
radiolarians, foraminiferans, budding. In mycelial forms, the pant
heliozoans. however, they may form a pseudomycelium by (sing. hypha).
hyphae
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structures called
Group 3. Sporozons body is made up of thread like
aseptate (non-septate) or septate. When non-septate
and
Characters: he mycelium may be
(1) All sporozoansare described as coenocytic.
endoparsites. multinucleate, the mycelium is non-septare Phycomycetae. In higher forms it is
(in) Some sporozans mycelium is eg.
such as Eimeria cause several
diseases like coccidiosis in lower fungi the Basidiomycotina and
Deuteromycotina.
in) Loconotory rganelles (cilia,
flagella.pseudopodia, in the birds. Septate e.g., Ascomycotina. is unicelled at one stage and mycelial at the other. Their
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(iv) Nutrition etc.)are absent. body

is prasitic (absorpiive). In some forms the plant
The body is avered with Phagoirophy is rare. described as dimorphic.
Organization is sometimes
(
an elastic pellicle or cuticle.
(ti) Contractile wcuoles are
absent
(vi) Asexual reroduction occurs
(ix) Life cycie onsists of wo through syngamy.
distinct
one (monogenet) or two difterenm asexual and sexual phases.
hosts (digenetic). They may be passea n
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Reproduction is primarily BIOLOGY
(6)
multicellukar. asexual
classification of Fungl. or sexual.
The
Describe the lticellular enbr ductive organs ar
S. multicellular einbryo S lormed

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Answer: (7) A during developnent
Classification of Fungi oryo stage. Lile cycle cOnSIsts from
of alternating the zygote. Algac
generation. This
te gencration.
SporopnytC haploid gametophyte lack
nis phenomenon and diploid
is called alternation of generation.
Describe the classification of Plantae.

AU
Answer: [MODEL QUESTION]
Fumycota Classilication of Plantae
(Axenuvt?

(vanuta)
Myecliumn
septate
LSt Wilhelm Eichler (1883)a Vinnese
ydoms mainly on the basis
botanist, divided
plant kingdom into two sub-
of presence or absence of secds.
Sline \Luids now
)Cryptogamae (ur. Cryplos hidden; gamos marriage):
eufudeu trer tungt UN Lower plants in which sex
nder Pnvisi
gans are hidden and seeds and flowers absent. It
pi includes Thallophytes. Bryophytes,
pteridophytes.
(2) Phanerogaimae (Gr. Phaneros visible; gamos =
marriage): Higher plants in which
Mycophycophyta sex organs are evident; seeds present. It includes Gymnosperms and Angiosperms.
AK
7y gomy cetes
Phy cumycetes
Conjugation fungi) (Dual organisms)
(omy ceres \lgd
cg. Rhizopus. NMucor I.ichens. e.g.. Thallophyta
tumgi Phytopithrs
Usnea, P'armelia
Alfugo. Pythium Comprises the sinplest plants which posess undifferentiated or thallus like forms.
Reproductive organs single celled no jacketed called gametangia
Embryo stage, vascular and mechanical tissues are all absent.
Deuteromycota
(Fungi imperfecti) Sexual
Differentiation of true roots, stems and leaves is also absent
reproduction absent. g. Asexual reproduction by accessory spores is very common. Presently. it includes
Alternaria. Cercospora only Algae.
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Microsporum. Trichophyton

Bryophytes
Ascomycota (Sac Basidiomycota (Club These are nonvascular terrestrial plants of moist
habitats in which a multicellular diploid
gametophyte that
sporophyte lives as a parasite on an independent multicellular haploid
fungi) Aspergillus. fungi) Puccinia.
Penicillium. Neurospora Ustilago. Agaricus
develops multicellular jackted sex organs.
29. Describe charactes
of plantae. [MODEL QUESTION Pteridophytes- pteridophyta
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Answer: plants that have sporophytic plant

Kingdom plantae includes green, Fteridophytes are seedless vascular or cryptogamic partially
brown and red algae, liverworts, containing small sessile antheridia and
plants with or without tlowers. mosses, ferns and seeu DOdy, inconspicuous gametophytes
They have the following nec.
() Multicellularorganisms with characters. cmbedded archegonia with 4- rowed
walled and frequently vacuolated
(2) They contain photosy eukaryotic cells.
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nthetic pigment in plastids.

(3) Principal mode surface
of nuurition is photosynthesis Gymnosperms in which the seeds remain exposed over the
absorptive. but number of plants
have beco e nnosperms are those seed plantslatter are not folded to form pistils.
(4) Primarily non-motile, megasporophylls because the
Tiving anchored
(5) Stnuctural ditferentiation to a substrate.
e
Angiosperms are formed inside fruits and the
support and in higncr leading towards plants in which sceds
foms towards specialised
organs of photosynthesis,
anchorage and giosperms are those seed
tissues. photosynthetíc, porophylls are organized into TIOueid
vascular and coveE
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TION BIOLOGY
Ansiver:

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Animalia.
31. Describe the Kingdom Viruses are obligale parasites.
Answer: organisms that addition to proteins
onc viruses also contain
heterotroptie cUkary are genetic material,
Kingdom Animalia charicterised by or DNA. that could be either
e RNA
is
nis kingdom lack cell wallsS their food No virus contains both RNA and DNA.
muticellular and their cells tor tood. hey digest
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depend on plants an virus is a nucieoprolein and the genetic

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directly or indirevthy or a. material is infectious. In general,
hey fand reserves as glycogen
that infect plants have single stranded RNA and viruses viruses
cavity and stor
enal is holoz0ie - by
ingestion of to0d.
*Iheir mode of nutrition growth pattern and grow into adults that have a definite shape either single or double stranded RNA or double stranded that infect animals have
DNA. Bacterial viruses or
hey tollow a detinite bacteriophages (viruses that infect the bacteria) are usually double stranded DNA
and size. mechanisnm viruses.
elaborate sensory and neuromotor
iigner torms show is by copulation of male and
female followed by embryolooi. The protein coat called capsid made of small subunits called capsomeres, protects the
The sexual reproduction
nucleic acid. These capsomeres are arranged in helical or polyhedral geometric
development. forms.
[MODEL QUESTION] Viruses cause discases like mumps, small pox, herpes and influenza. AIDS in
AK
32. Define the following terms.
Answer: humans is also caused by a virus. In plants, the symptoms can be mosaic formation,
Anaemia: Animals without red blood e.g, sponges, cnidaria, mollusca, arthropoda, leaf rolling and curling, yellowing and vein clearing, dwarfing and stunted growth.
echinodermata etc.
34. What is Virods and what is Lichens? [MODEL QUESTION]
Enaima: Animals with red blood e.g., vertebrate
Vivipara: Animals which give birth to young ones are included in this subgroup e.g. Answer:
man. dogs. cows. etc. Viroids: In l971 T.O. Diener discovered a new infectious agent that was smaller
found to be a free RNA;
than viruses and caused potato spindle tuber disease. was
Ovipara: Animals which lay eggs are included in this subgroup e.g.. It
frogs, toads, in viruses, hence the name viroid. The RNA of
lizards. snakes. birds. etc. it lacked the protein coat that is found
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Anamniotes: Vertebrates without embryonic membranes the viroid 'was of low molecular weight.
e.g., fishes, amphibians. i.e, mutually useful associations,
Amniotes: Vertebrates with embryonic membranes
(chorion, amnion, allantois, yolk Lichens: Lichens are symbiotic associations is
sac) e-g. reptiles. birds, mammals. fungi. The algal component known as phycobiont and fungal
between algae and respectively.
Acraniata or Protochordata: Chordates as mycobiont, which are autotrophic and heterotrophic,
without cranium (brain
box). It includes Component absorb mineral nutrients
urochordata and cephalochordata.
prepare food for fungi and fungi provide shelter and
Chordates: Animals with notochord Algae
dorsal tubularnerve cord, paired pharyngeal and water for its partner. areas.
slits. g indicators - they do not grow in polluted
All urochordates, Lichens are very good pollution
cephalochordates
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and vertebrates are

Craniata or Vertebrate: called chordates. Unicellular and Multicellular Organisms.
It Includes cyclostomes.
Chordates with cranium. 35. State the difference between [MODEL QUESTION]
pisces, amphibians,
Nonchordates: Animals reptiles, birds and
supports without notochord mammals. Answer:_
the body). Phylum Porifera (a rod like elastic structure ch Multicellular Organisms
nonchordates. w
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to phylum Hemichordata are Unicellular Organisms

Invertebrates: Animals is composed of
urochordates and without vertebral The body of the multicelular organism
cephalochordates column (backbone). The body of the
are collectively All the noncnor lates. is
numerous cells.
called invertebrates. unicellular organism
33. What are the
features of Virus? composed of a single cell.
[MODEL QUESTION] Have a definite shape.
rregular in shape

s10-38 BIO-39
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Answer:
The
TTC term prokaryote
"proka is derived from
"karyn(n (meaning: kernel). lt translates the Greek word "pro", (meaning:
before) and
yotic cells are comparalively smaller
Proka
to "before nuclei."
r
other defining characteristic of prokaryotic
and much simpler
than eukaryotic cells. he
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cell cells is that it does

organelles such as a nucleus.

S
bound not possess membrane
Reproduction happens
binary fission. through the process otof

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Structurally. prokaryote; have a capsule enveloping
protective coat. This is its entire body, and it functions as a
crucial for preventing
the process of phagocytosis
bacteria gets engulied by other (where the
eukaryotic cells such as
macrophages.) The pilus is a hair-
ike appendage found on the external surface of
organism to attach itself to various most prokaryotes and it helps the

TI
environments. The pilus essentially
flushed, hence, it is also called attachment resists being
pili. It is commonly observed in bacteria.
Right below the protective coating lies the
cell wall, which provides strength
and rigidity
to the cell. Further down lies the cytoplasm
contained within the plasma membrane, which
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from the outside environment. Within the cytoplasm,
that helps in cellular growth, and this
separates the interior contents of the cell

important role in protein synthesis. It is also one of the

ribosomes exist and it plays an
smallest components within
is

the
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cell.
Some prokaryotic cells contain special structures called
mesosomes which assist in
cellular respiration. Most prokaryotes also contain plasmids, which
contains small,
circular pieces of DNA. And to help with locomotion, flagella are
present, though, pilus
can also serve as an aid for locomotion. Common examples
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of Prokaryotic organisms
are bacteria and archaea. Also, all members of Kingdom Monera
are prokaryotes.
37. What is Eukaryotic Cell? [MODEL QUESTION]
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Answer:
The term "Eukaryotes" is derived from the Greek word "eu", (neaning:
good) and
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karyon" (meaning: kernel), therefore, translating to "good or true nuclei." Eukaryotes

are more complex and much larger than the prokaryotes. They include almost all
the
major kingdoms except kingdom monera.
Structurally, eukaryotes possess a cell wall, which supports and protects the plasma
membrane. The cell is surrounded by the plasma membrane and it controls the entry and
exit of certain substances.
e

he nucleus contains DNA, which is responsible for storing all genetic information. The
hucleus is surrounded by the nuclear membrane. Within the nucleus exists the nucleolus,
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ind it plays a crucial role in synthesising proteins. Eukaryotic cells also contain
mtochondria, which are responsible for the creation of energy, which is then utilized by
the cell.
Tesent in only plant cells, chloroplsts are the subccllular sites of photosynthesis.
LSndoplasmic reticulum helps in the transportation ot materials. Besides these, there are
also
also other cell organelles that perform various other functions and these
BIO-41
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viicuoles,
citopIasnm, and Prokaryotes
balies, BIOLOGY
lysosomes. Ciolgi

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0eS,
centrosomes. every uicellular
nism with.
organism with a nucleus and a
Reproduction Asexual Eukaryotes
alnrost
Examples of cukary otces inclue
Both asexual
multicellular organisnts. Example Bacteria and and sexual
Eukaryotic CelIs. Archaea
Prokaryotic and MODEL QUESTIONI
between Plant and Animal
0. State the Difference cell

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39. Classity the organism on the
basis of C source
Answer: and N source.
Eukaryotes
Prukaryotes Ansiwer: [MODEL QUESTIONI
Unicellular and multi-cellular SubType
Alwaps uniceliular Heterotroph Photoheterotroph Csource N SOurce
Type of Cell Example
Preformed Sunlight
Ranges in size from 0.2 um
-
2.0 SIze anges from 10 um--100 um organic
Purple non-
Cell size in diameter sulfur bacteria
LuIm in dianieter
molecules
e.g. sugars
chemolithoheterotroph
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Cell wall Usually present: chemically When present, chemically mple Pretormed Oxidation of
cemplex in nature in nature organic inorganic
molecules compounds
Nucleus Absent Present
chemoorganoheterotroph
Cg ugars Cg. H:S
Preformed Oxidation
organic organic
of
Ribosomes Present. Smaller in size and Present. Comparatively larger in molecules
spkerical in shape size and linear compounds
in shape e.g. Sugars
Autotroph Photoautotroph Carbon Sunlight
ONA arrangement Circular Linear (lithotroph)
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dioxide
Chemoautotropth Carbon Oxidation ot
litochondria Absent
Present dioxide
methanogens
Inorganic
Cytoplasm Present, but cell organelles absent compounds.
Present. cell organelles present
Endoplasmic 40. Define aminotelic, uricoteliec and ureotelic. [MODEL QUESTION]
Absert
reticulum Present Answer:
ammonotelic organism exeretes nitrogenous waste as soluble ammonia. Most of the
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Plasmids
Pre>ent qualic animals including protozoans, crustaceans, platyhelminths, cnidarians, poriferans,
Very rarely found in eukaryotes CCninoderms, fishes, larvae / tadpoles of amphibians are ammonotelic.
Ribosome
Small nbOSomes
Large ribosomes as urea. Urea is less toXIC and needs less
Ly sosomne ureotelic organism excretes excess nitrogen
include cartilaginous fish, few
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In this. the lysosome.

mesosome. aer in comparison to Ammonia. Ureotelic organisms
humans. The uricotelic organism
and cemrOsome is
absent
MesOsome, Lysosomes, and .0ny fishes, adult amphibians and mammals including
centrosomes are present to Ammonia and Urea, Uric acid is the least
Cell division
Through binary fission
reres uric acid or its salts. In comparison
It can be stored in cells and body tissues without
IC and the least soluble in water.
and is highiy efticient mode of excretion
in
Through mitosis
Flagella effects and tlhus needs least water
he flagella are smaller AC ethods.
in size omparison to two other melh
The flagella are larger in size

BIO-43
BIO-42
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POPULAR PUBLICATIONS (imclhuding insects
cts), lizar snakes mamma
arthreorls only 1n E. colt are
paste. able to survive in

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terrestrial While raustic and used in digestion. the presence of bile salts, which arc
include picaly'
organisms organisms is ty
Urice
The encreta
of
uricotelic
IMODEL QUESTION addition tothriVing in the colon, E.
colican also survive outside the
irus, Cnvironmental E. coLi can be spread bouy
through feces as
Classification? the bacteria pass out of the bouy
. What is Molecular composition o
distributnon and compositi0n of chemnieat
hese two habitats are about as opposite as you
can get. The colon is relatively
stadi
basis of warm, anaerobic, and nutrient-rich. Outside
Answer: the of the colon, conditions can be extremeiy

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organism on harsh and variable, much colder, aerobic,
TheCassitication of Classilication. and provide fewer
callead Molecular nutrients.
Substances in them is organism2
significance of model Model Organism
organism? What is the [MODEL QUESTION
%. What is Model The fact that E. coil is able.to survive such variable conditions is one advántage that ied
Answer: extensively studied to undr
ierstand to its use as a model organism. A model organism is a species that is extensively studied
that is
is a non-human specics to understand a specitic phenomenon, expecting that the knowledge gained can be
Amodel organism discoveries made in the model
with the expectation that
particular biological phenomena. applied to other species as well.
insight into ihe workings of otner organisms. Model organisms are
organism will provide unfeasihla E. coli has many attributes that make it an ideal candidate for use as a model organism.
when human experimentation would be sible
idely usei to research human disease
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the common descent of all li Let's discuss the five major atributes that make E. coli an excellent model organism.
is made possible by
or unethical. This strateg
genetie Attribute 1: E. coli is a single-celled orgunism. There are no ethical concerns about
and developmental pathways and
organisms. and the conservation of metabolic growing, manipulating. and killing bacterial cells, unlike multicellular model organisms
material over the course of evolution. like mice or chimps. They are also tiny cells, so in a small laboratory you can have flasks
Studying iadel organisms can be informative, but care musl be laken when generalizing
containing billions of celis that take up very little room, allowing many experiments.
from one organism to another.
In researching human disease. model organisms allow for better understanding the Aturibute 2: E. coli is able to reproxduce and grow vey rapidhy, doubling its population
disease process without the added risk of harming an actual human. The species chosen about every 20 minutes. This is helpful in a lab situation where waiting for subsequent
generations to produce experimental data can be the rate-limiting step. With E. coli
it is
will usualy meet a detemined taxonomic equivalency to humans, so
asto react to as easy and fast as letting them grow overnight. Trying to study the same process in
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disease or its treatment in a way that reseimbles human physiology as needed.

of
Although biological activity in a model organism does not ensure subsequent generations of elephants, for exanple, would require several generations
an etfect in humans,
many drus. treatments and cures for human
diseases are developed in part with the scientists and more elephants than we have on the planet!
earlier,
guidance of animal models. There are three main
types of disease models: homologous, Allribute 3: E. coli can survive in variuble growth conditions. As we discussed
Culture media
isomorphic and predictive. Homologous animals
have the same causes, symptoms and this leads to it being very adaptive yet forgiving in lab situations.
successtfully spur E.
treatment options as would humans
who have the same disease. containing simple and inexpensive ingredients and nutrients cain
the same symptoms and Isomorphic animals share and divide.
treatments. Predictive models coli to grow
are similar to a particular human are hurmless. Those food-
disease in only a couple
of aspects, but are useful in Attribuie 4: Most naturally occurring sirains ofE. coli
isolating and making prediction are the exception, not the rule. When
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about mechanisms of a
set of disease features. poisoning E. coli that sprang to mind earlier
chose a strain that was
scientists first started using E. coli for lab experiments. they
43. Why Escherichia Coli E. poses Iittle threat to researchers and the public.
Answer:
is selected as model
organism? harmless. This means that studying coli
[MODEL QUESTION
Escherichia coli,.or E. coli Why it is considered as model organism?
for shorn, is a Gram-negative, 44. Describe Saccharomyces cerevisiae.
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normal inhabitant
of rod-shaped bacteria that [MODEL QUESTION]
estimate that E. coli he lower yastrointestinal tract of warm-blooded itists
first evolved between animals. Answer:
years ago, aboutsci same as baker's yeast) is a single-celled
time as the appearance 120 and 160
of mammals. It is likely million Saccharomyces cerevisiae (commonly known
of mammals for theentire that E. coli
the relatively rare abtity history of both groups. Further has been living in
ns eukaryote that is frequently used in scientilic
research. S. cerevisiae is an attractive model
ofE. coli to utilize lactosc, n
evidence for his syyo e is organism due to the fact that its
genome has been sequenced, its genetics are easily
lab. Because many yeast proteins are
d manipulatcd, and it is very easy to maintain tne other organisms, studies performed in
in
which
is the sugar ot
mik to those found in
Similar in sequence and function
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There are many reasons the fruit fly is a
POPULAR PUBLIÇATIONS protein functions in higher Its care and culture choice as a model
or require little equipment, orgnism:
particular gene large cultures. space, and expense pven wne
a hen uSing
determine how scores tavourabl,
tavourably on

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yeast can help us to it sCores ..It can be safely and readily anesthetized
eukaryotes (including hunans). model
organism becuse (usually with ether, carbon
as a cooling, or with products such dioxide gas, D
Cereiusiue has developed short generatio time
as FlyNap).
small wina s morphology is easy to identify once anesthetized.
number of these criteria organism, S. cervisiae is
and can be easily cultured These It has a short generation time
AS a
single-cell °C or 86 °F) production and (about 10 days
hours at 30 tne sWit generations can be at room temperature), so severa
(doubling time 1.25-2 they allovW Tor
in that studied within a few weeks.
characteristics

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are all positive specimen lines at
lowV COSt. sev It has a high fecundity (females lay
up to 100
maintenance of multipe a candidate for sexual eggs per day, and perhaps 2000 in a
meiosis, allowingl to be lifetime).
Cerevisiae divides with Males and females are readily distinguished,
either the addition of new gene or
genetics research. and virgin females are easily isolaed
can be transformed
allowing for facilitating genetic crossing.
Cererisiu recombination. Furthermore, the ability to
deletion through homologous strains.
The mature larva has giant chromosomes in the salivary glands called
simplifties the creation of gene knockout
polytene
grow S. cerevisiae as a huploid chromosomes, "puffs", which indicate regions of transcription, hence gene
the complex internal cell structure of plants It has only four pairs of chromosomes
activity.
As a cukaryotc. S. cerevisiae shares DNA that can confound
-
three autosomes, and one pair of sex
and animals without the high percentage of noi-coding chromosomes.
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research in higher eukaryoles. Males do not show meiotic recombination, facilitating genetic studies.
S.cerevisiae research is a strong economic driver, at lecast initiany, as a result of Recessive lethal "balancer chromosomes" carrying visible genetic markers can be
its established use in industry.
used to keep stocks of lethal alleles in a heterozygous state without recombination
due to multiple inversions in the balancer.
45. Describe Drosophila melanogaster. Why it is considered as model organism?
[MODEL QUESTION] The development of this organism-from fertilized egg to mature adult-is well
Answer: understood.
Drosophilu melanogaster is a species of fly (the taxonomic
order Diptera) in the
Genetic transformation techniques have been available since 1987.
family Drosophilidae. The species is known
generally as the common fruit.fly Its complete genome was sequenced and first published in 2000.
(though
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inaccurately) or vinegar ly. Starting Sexual mosaics can be readily produced, providing an additional tool for studying the
with Charles W. Woodwortli's
of this species as a model organism. D. proposal of the use
melanogaster continues to be development and behaviour of these flies.
biological research in
genetics. physiology, microbial
widely used for
evolution. pathogenesis, and life history
D. melanogaster
Genetic markers
is typically used in research Genetic markers are commonly used in Drosophilu research. for example within balancer
laboratory. has only because it can be
four pairs of chromosomes, readily reared in the
geographic range includes breeds quickly, and chromosomes or P-element inserts, and most phenotypes are easily identifiable cither
all continents, including lays many eggs. its with the naked eye or under a microscope. In the list of a few common markers below,
pest in homes, restaurants, islands. D. melunogaster
is a commo
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and other places where the allele symbol is followed by the name of the gene affected and a description of its
Flies belonging food is served.
to the family Tephritidae
confusion. especially are also calied phenotype. (Note: Recessive alleles are in lower cas. while dominant alleles are
"fruit
Mediterranean fruit fhyin the Mediterranean, Australia, flies". This can cause
capitalised.).
Ceratitis capilata and South Africa,
is an economic
pest.
where tne Cy: Curly: the wings curve away from the body. flight may be'somewhat impaired
D. melanoguster e: Ebony: black body and wings (heterozygotes are also visibly darker than wild
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remains one
particularly in of the, most studied type)
genetics and developmental organisms
biology. in biological Sb: Stubble; bristles are shorter and thicker than wild type
casons for researi
model w: White; eyes lack pigmentation and appear white
melanogaster organism
types (clockwise): bw: Bron; eye color determined by various pigments combined.
es with ebony
body. vermilion eyes,Brown eyes with black y: Yellow; body pigmentation and wings appea yellow, the fly analog of albinisnm
white eyes, body, cinnabar
and wild eyes, s
BIO-46 type eyes with
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the
molecular biology of many BIOLOGY
cause hen mutaled, plant traits,
phenotype they

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atler the Sensing including flower
Classic genetic nutations
traditionally named Droxyiilau w ill result in a mu ant development and light
Drusophilu gensarei
urticular gene
in
gene timnan 1:3med
the absence of a called isS dbaliana is now wiaeiy
For Seiemists have thus Stvenbahy Rena ene.dcause used lor studying plant
develop a heart. in the
ryothatdves not the sune name. likew ise ehnges lation genetics, and
plant development.
sciences,
including genetics,
karvae. This system nificance evolution
er the Qy character of hairs in roseyhilu
stchlni
organisms.
of for agriculture, it Although A.
has several traits thuliuna has little direct
of
loss dorsal cuticular than in otner derstanding the genetic, cellular, that make it a. useful

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the gen names
wider runge of and molecular biology model tor
ITiCature results in a of flowering plants.
Similarity to humans compariing the frui Reasons for model organism
Human Genome Research institute Genomics
A Marc 2000 studs by National betiveen the tivo
two
tly and human genome estimatad that about 60% of genes are coiServed Nuclear genome
disease genes have a recognizable match
in the
species. About 75°» of known human The small, size of its genome, and the fact
sequences have mammallan honologs. An that it is diploid. makes Arabidopsis
genome ot truit flies. and s0°s of tly protein thaliana useful for genetic mapping and sequencing-
online catabase called Homupila is available to. search
for human disease gene with about 135 mega base
pairs and five chromosomes, A. thaliana has one
homolegues in tlies and vice versa. Drosophila is being used as
a genetic model for of the smallest genomes among plants.
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It was long thought to have the smallest genome
Several human diseases including the neurodegenerative of all flowering plants, but that title is
now considered to belong to plants in the genus Genlisea, order Lamiales,
disorders Parkinson's. Huntington's. spinocerebellar ataxia and Alzheimer's disease. The with enlisea
tuberosa, a carnivorous plant, showing a genome size of approximately 61 Mbp. It was
ly is also being used to study mechanisms underlying aging and oxidative
the first plant genome to be sequenced, completed in 2000 by the Arabidopsis Genome
Stress. immunity. diabetes. and cancer. as well as drug abuse.
Initiative. The most up-t0-date version of the A. thaliama genome is maintained by the
46. Describe Caenorhabditis elegans. MODEL QUESTION]
Arabidopsis Information Resource (1TAIR). Much work has been done to assign functions
Answer: to its 27,000 genes and the 35,000 proteins they encode. Post-genomic research, such as
Caenorhabdiris elegaus is a free-living. transparent nematode, metabolomics, has also provided useful insights to the metabolism of this species and
about I mm in length, that
fives in temperate soil environments. It is how environmental perturbations can affect metabolic processes.
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the type species of its genus. The name is a

blend of the Greek caeno-
(recent). rhabditis (rod-like) and Latin
1900. Maupas initially elegans (elegant). In Chloroplast genone
named it Rhabditides eleguns, Osche
the subgerus C'uenorhabditis placed it in The plastome of Arabidopsis thaliana is a 154. 478 base pair long DNA molecule, a size
in 1952, and in 1955, Dougherty
raised Caenorhabdilis to
typically encountered in most flowering plants. comprises 136 genes coding for small
the status of genus. It

C. eleguns is an unsegmented
pseudocoelomate and lacks, Subunit ribosomal proteins (rps, in yellow), large subunit ribosomal proteins (rpl,
respiratory or circulatory proteins
systems. Most of these
nematodes are hermaphrodites orange), hypothetical chloroplast open reading irame proteins (vcf. lemon),
specialisedtails for mating and a few are males. ribosomal RNAs
that include spicules. Males have nvolved in photosynthetic reactions (green) or in oher functions (red).
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47.
rrn, blue). and transfer RNAs (n, black).
DescribeArabidopsis
thaliana. Why it is considered
as model organism? Mitochondrial genome
Answer: is š67,808 base pairs long and
Arabidopsis thaiana, [MODEL QUESTIONJ The mitochondrial genome of Arabidopsis thaliana
many repeated regions in the Arahilopsis mitochondrial
small flowering plant the thale cress, mouse-ear contains 57 genes. There are
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genome. Like most

nativeto Eurasia
tound by roadsides and in disturbed and Africa. A. thuliana
cress or arabidopsis, is a genome. The largest repeats recombine regularly and isdmerize the
genome exists as a complex
A winter annual With land. is considered a wced, it is plant mitochondrial genomes., the Aranictopsis mitochondrial
a reatively molecules in vivo.
organism in plant short life arrangement of overlapping branched and linear
bioiogy ana genetics. cycle, A. thulianu is rouine. utilizing Agrohacterium tumefaciens to
thaliana has a relatively For a complex a popular odel Genetic transformation of A. tholiana iS
genome i transfer DNA into the plant
genome. Ine crrent protocol, termed "floral dip". involves
was the irst plant to navesma1 of approximately multicellular eukaryo
a Cotaining AgrObacterim carrying a plasmid of
iS
EOme sequenced. 135 megabase
pairs (Mo Simply dipping flowers into soiuuon
and is a popular
tool for understana BIO-49
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POPULARPUBLICATIONS lor tissue plam (Dilute, Brown and
BIOLOGY
the need

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uu) inbred mouse
method avoids generation of inbred strains. The mouse strain and initiated
This the matic
nterest and a detergen anism and is associated has since been
with many important used extensively as a model
rgenertion. 21st Centuries. biological discoveries
DIology made of the 20th and
0pt
resolurce
m3 The Jackson Laboratory in
are a unique Bar Harbor, Maine
Geneties Knockout eollections for genomin is
ndliuimi gene transtormation and runalng Suppliers of laboratory mice, at around 3 currently one of the world's largest
nc.. high-hroughput over 300.000 million mice a year.

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availability of 0r world's source for more than 8,000 strains The laboratory is also the
OSSible by the insertions has been
deterinea
resourves. The site of T-DNA and seeds accessioie through online T. the Mouse Genome Informatics database.
of genetically defined mice and is home o
with the information nmutants are available for mocs
hdependent transgenic lines. collections. insertional
st
DNA datakases. Through these
Senes im.i. tiailii.
it is considered
as model organism since lona
43. Describe Mus musculus. Why [MODEL QUESTION)
time?
Answer: the order Rodentia.
is a small mammal of
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the house mouse (Jfus musculus)
ears. and a long and hairy tail. It
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charactenstically hav ing a pointed snout, large rounded

1S one of the most abundant species of the genus
Alus. Although a wild animal, the house
to the point
mouse has benetited signiticantly from associating with human habitation
that truly wild popuations are significantly less common than the semi-tame populations
rear human activity.
The house mouse has been domesticated as the pet or fancy mouse, and as the laboratory
mouse. which is one of the most important model organisms in biology and medicine.
Thecomplete mouse reference genome was sequenced in 2002.
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Mice have been used in biomedical research since the 16th Century
when William
Harvey used them for his studies on reproduction and
blood circulation and Robert
Hooke used them to investigate the biological
consequences of an increase in air
pressure. During the 18th century Joseph Priestley
and Antoine Lavoisier both used mice
to study respiration. In the 19th
century Gregor Mendel carried out his eariy
investigations of inheritance on mouse coat
color but was asked by his
breeding in his cell "smelly creatures superior to Stop
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that, in addition, copulated

switched his investigations to peas and had sex". He then
but, as his observations were
obscure botanical jourmal, they were published in a somewnat
virtually ignored for over
rediscovered in the early 20th 35 years until they were
century. In 1902 Lucien Cuenot
experiments using mie which published the results otrni
showed that Mendel's laws
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for animals-results that of inheritance were also vand

were soon contirmed
and extended to other
species.
In the early part of
the 20th century, Harvard
conducting studies on mouse undergraduate Clarence
genetics in the laboratory Cook Litile wa
and Castle collaborated closely of William Ernest Castle.
with Abbie Lathrop L
rats which she inarketed to who was a breeder
selling in large numbers
rodent hobbyists
and keepers of fancy imice a
toSenilic researchers. Together of exotic pets, and later
beg
they generated the LDD
BIO-50 BIO-51
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Multiple Choice

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Type Que ions
GENETICS 1. The tendency of an offspring
to resemble its parent
is known as
a) Variation [MODEL QUESTIONJ
b).Heredity
c) Resemblance
d) Inheritance
Answer: (b).

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Chapter at a Glance
process by which this occurs is 2. Who is known as the "Father of Genetics"?
arise fhom
preevisting cells. The
ACCording to the celi theory. cells lie cycie rom a single-celled [MODEL QUESTION
reproducing oryanism starts its a) Morgan b) Mendel
caled cell division. Any sexually
mature orgams.dut continues Watson d) Bateson
ZYSote. Cell division does not stop
with the formation of the Answer: (6)
throughout its lite cycle.
3. The alternate form of a gene is [MODEL QUESTION]
division to the next is called thecell cycle. Cell
The stages through w hich a cell passes from one a) Alternate type b) Recessive character
period of preparation for cell division,
Cyee is diided into tvwo phases called (i) Interphase-a lurther subdivided into
c) Dominant character d) Allele
and ( tosis (NI phase) - the actual period of cell division. Interphase is Answer: (b)
and G2.Gl phase is the period when the cell grows and carries out normal metabolism.
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G.S
Nlost of the organelle duplication also occurs during this phase. S phase marks the phase of
DNA.
4. The genotypic ratio of a.monohybrid cross is [MODEL QUESTION]
replicatien and chromosome duplication. G2 phase is the period of cytoplasimic growth. Mitosis is d) 9:3:3:1
also div ided into four stages namely prophase, metaphase, anaphase and telophase. Chromosome
a) 1:2:1 b) 3:1 c) 2:1:1
condensation occurs during prophase. Simultaneously. the centrioles move to the oppOsite poles. Auswer: (a)
The nuclear envelope and the nucleolus disappear and the spindle fibres start appearing [MODEL QUESTION]
Metaphase is marked by the alignment of chromosomes at the equatorial plate. During anaphase 5. The crossing of F1 to any of the parent is known as
a) Test cross b) Back cross
tne centromeres divide and the chromatids start moving towards the two opposite poles. Once the d) All of the above
chromatids reach the two poles. the chromosomal elongation starts, nucleolus and the nuclear c) F1 cross
membrane reappear. This stage is called the telophase. Nuclear division is
then followed by the, Answer: (d)
cytoplasmic division and is called cytokinesis. Mitosis thus, is
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the equational division in which the

chromosome number of the parent is conserved in the 6. Which of the following statements is true
regarding the "law of segregation"?
daughter cell [MODEL QUESTION]
In contrast to mitosis, meiosis occurs in
the diploid cells, which are destined to a) Law of segregation is the law of
purity of genes
called the reduction division since it reduces form gametes. It is during gametogenesis
the chromosome number by haif b) Alleles separate from each other
gametes. n sexual reproduction when while making tne to the segregatjon of chromosomes during
the value in the parent. Meiosis is
the two gametes fuse the chromosome
number is restored to c) Segregation of factors is due
divided into two phases meiosis I meiosis
meiotic division the homologous and meiosis I1. In the first
Meiosis has a long prophase,
chromosomes pair to form bivalents,
and undergo crossing ove d) All of the above
which is divided further into five Answer: (d)
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zygotene. pachytene, diplotene

and diakinesis. During metaphase I phases. These are leptotene,
equatorial plate. 1his is followed the bivalents arrange on of an individual can be determined by
opposite poles with both their by anaphase I in which
homologous chromosomes 7. Homozygosity and heterozygosity [MODEL QUESTION
chromatids. Each pole receives
the chromosome number to
Imove
parent cell. In telophase the nuclear half or t b) Self-fertilization
mitosis. During anaphase lH
I, membrane and nucleolus
a) Back cross
the sister chromatids reappear. Meiosis II is d) All of the above
cells are formed. separate. Thus at the end similar c) Test cross
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of meiosis fourhapio Answer: (a)

EMODEL QUESTION]
Mendel's law is
8. An exception to assortment b) Linkage
a) Independent d) Purity of gametes
c) Dominance
Answer: (b)
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POPULAR PUBLICATIONS (MODEL 17. If a plant with genotype
because
experiments contrasting characters genotype will be (A and B are AaBb is selfed,

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Mendel's not linked) the probability of
9. Pea plants were Used in had a) getting AABB
b) They above b) [MODEL QUESTION
a) They were cheap d) All of the Answer: (b) c) %
They were available easily
C)
d) 1/16
Answer: (6) phenotypic effect on 18. How many phenotypes can
which produces a [MODEL QUESTION] A13? occur in the human
genetic material blood group ABO with alleles
maSmaliest unit of d) Nucleic acid a) 2

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b) 3 [MODEL QUESTION
mutation is c) Reconn c)4
a) Muton b) Gene Answer: (d) d) 1
Answer: (c)
MODEL QUESTION] 19. The geometrical device
that helps
11. Mendel's findings were rediscovered
by male and female gametes is known as to find out all the possible combinations of
b) De Vries a) Bateson Square IMODEL QUESTION]
a) Correnss d) All b) Mendel Square
c) Tschermark c) Punnett Square
d) Mendel Square
Answer: (d) Answer: (c)
[MODEL QUESTION]
12. Alleles are 20. Which term represents a pair of contrasting
characters? [MODEL QUESTION]
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a) Alternate forms of genes a) Heterozygous b) Homozygous
b) Linked genes c) Codominant genes d) Allelomorphs
C Chromosomes that have crossed over Answer: (d)
d) Homologous chromosomes
Answer: (a)
LShort & Long Answer Type Questions
13. When the activity of one gene is suppressed by the activity of a non-allelic
gene, it is known as [MODEL QUESTION] 1. What is Genetics? [MODEL QUESTION]
a) Pseudo-dominance Hypostasis
b) Answer:
c) Epistasis d) Incomplete dominance Genetics is a branch of biology concerned with the study of genes, genetic variation, and
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Answer:(C)
heredity in organisms.
14. Cystic fibrosis is
[MODEL QUESTION] 2. Define Mendel's Law. [MODEL QUESTION]
a) Sexiinked recessive disorder b) Autosomal dominant disorder
c) Autosomal recessive disorder d) Sex-linked dominant disorder Answer:
Answer: (c) Mendel's Law of Segregation states individuals possess two alleles and a parent passes
only one allele to his/her offspring. Mcndel's Law of Independent Assortment states
15. 9:7 ratio in the F2
generation represents the inheritance of one pair of factors ( gencs ) is independent of theinheritance of the
a) Incomplete dominance [MODEL QUESTION]
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b) Co-dominance other pair.

c) Epistasis
Answer: (¢) d) Complementary
interaction [MODEL QUESTION]
What do mean by discrete inheritance and Mendel's laws?
3.
16. A small amou Answer:
At its most fundamental level, inheritance in organisms occurs by passing discrete
of lethat mutation is ahways present
in the population due to
heritable units, called genes, from parents to orispring. This property was first observed
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a) Positive selection [MODEL QUESTION

c) b) Negative selection by Gregor Mendel. who studied the segregation of heritable
traits in pea plants. In his
Frequency-dependent selection the flowers of each
Answer: (d) d) Mutation-selection experiments studying the trail for flower color, Mendel observed that
balance pea plant were either purple or whitebut
never an intermediate between the two colors.
same gene are called alleles.
These different, discrete versions ol the
In the case of the pea, which iS aiploid Species. each
a individual plant has two copies of
Iromm each parent.Many species. inçluding humans. have
each gene, one copy inlherited
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Of the Same llele of a
two copiC's two.different Answer:
orgunisms nitlh organusnis with [MODEL QUESTION]

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this atterm of
inheritance. Diplo locus, vhile An allele 1s a variant iorm
ol a gene. Some genes
homozygous at that ge* are locatea at the Same have a variety of ditferent
given gene are ealled goUS. gemtype, while
tHhe obse
observable traits posilion, or genetic locus, forms, wnici
are called heteroz\ diploid organisms because
alleles of a given gene its
organisn is callet organisnis are heterozyg gous at a gene. they have two on a chromosome.
Humans are caeu
The set of alleles
tor a given hen inherited from each parent. alleles at each genetic
are called its phenoty
pe
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domiate ne phenotype of the Each pair of alleles locus, with one aci
qualities Genotypes are described as homozygous represents the genotype a
of the organism is called
dominant as its qualities receae and
are not
if there
of specilic gene
often ene allele rcessive as Ils locus and as heterozygous if the two are two identical alleles at a particular

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while the other allele is called dominance and instead nave incomplete alleles differ. Alleles contribute
organism. complete phenotype, which is the outward to the organisms
not have oy expressing both appearance of the organism.
observed. Some alleles do intermediate phenoty pe. or codominance Some alleles are doiminant or recessive.
an
dominance by expressing locus and caries one dominant and one
When an organism is heterozygous
at a specitic
one of the
alleles at once. otfspring randomiy inheril recessive allele. the organism will express
repraduce sexualiy, their inheritance and the dominant ,phenotype. Alleles can also refer tne
When a puir of organisms observations of discrete alleles that do not necessarily influence to minor DNA sequence variations between
trom each parent. These or the Law of the gene's phenotype.
tvo alleles known as Mendel's irst lav
segreyation of alleles are colletively
7. What is gene mapping used for?
Seyregation. [MODEL QUESTION]
Answer:
[MODEL QUESTION]
Genetic maps are a necessary tool for mapping of disease genes or trait loci, a
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4. What are the different Mendel's Laws?
Answer: two laws:
.
also commonly known as linkage mapping. Integrating genetic
method
mapping and
An analysis of genetie crosses
depends upon an understanding of Mendel's disease gene mapping with next-generation sequencing has proven to be a powerful
seyregation {First Law): The two members of a gene pair (alleles)
The principle of strategy in genetic rescarch
seyregate (separate) trom each other in the
formation of gametes. Half the gametes
carry the other allele.
carry one alleie. and the other haltf 8. How do researchers create a genetic map? [MODEL QUESTIONI
The principle of independent assortment (Second Law): Genes for different
traits
Answer:
assort independently oi one another in the forination of gametes. 1o produce a genetic map, researchers collect blood or tissue samples from members of
In practice, the manitestation of Mende!'s laws is seen by characteristic ratios of families in which a certain disease or trait is prevalent. Using various laboratory
phenotypic classes. such as 3:1 and 9:3:3:1. Further, the Mendelian principles just
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techniques, the scientists isolate DNA from these samples and examine. it for unijue
stated include the simpe assumption that one allele is dominant to the other allele. patterns that are seen only in family members who have the disease or trait. These
In the time since Mende's original experiments, we have come to learn that there are characteristic. patterns in the chemical bàses that make up DNA are referred to as
extensians to Mendelian principles. including the fact that some alleles are markers.
ncompletely dominant. that some genes are sex-linked, and that some pairs of genes DNA markers don't, by themselves, identily the gene responsible for the disease or trait:
do not assort independently because they are physically linked on a
chromosome. but they can tell researchers roughly where the gene is on the chromosome.
a
5. What is gene and its function? This is why: when eggs or sperm develop. the paired chiomosomes that make up
person's genome exchange stretches of DNA. Think of as a shuffling process, called
it
[MODEL QUESTION]
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Answer:
Genes are a set of instructions that determine
recombination. The single chromosome in a reproduciive cell contains some stretches of
what the organism is like, its appearance some from his or her father.
how it survives. and howit behaves DNA inherited from the person's mother and
in its environment. Genes are made of a a DNA marker, the gene and marker will likely stay
called deoxy ribonucleic acid or DNA. They substance If a particular gene .is close to
will likely be passed on together
molecules called proteins
give instructions for a living being to makc together during the recombination process. and they
with a particular disease or trait also inherits
from parent to child. If each family member
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a particular DNA marker. it IS very likeiy

that the gene responsible for the disease lies
Genes are actually unit of heredity
which is transferred from
springs. Genes are found in the chromosomes, parents to the
this chromosomes are found in
o near that marker.
The more DNA markers there a
are on a genetic map, te more likely it is that at least one
of a cell. Function of genes are the nucieu gene-ana the easier it will be for researchers to
to give specific character marker will be located close to disease
from their parents, like eye color. no. OT to the off-springs the irst major acnievements of the HGP was to
develop
imbs, haircolor, etc. zero in on that gene. One of
eveniy cross tne entire human
genome.
markers spaced
dense maps of
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in human height, skin in nature
color, and ound in many places
hair color;
9. What is Gene
Interactions?
aoscnce o another
gene in n
resistance. ana _plants
these traits are intluenced
with grain in animal size,
color, length of maize, longevity, o isease
pesence vr loci th by multiple genes or flower size. A of
Answer: Interactions: at ditterent and considered polygenic.
Meaning of Gene one gene depends on the interaction oT gencs
13. Why Is body size
expressionknown of gene interaction. 1he plhenotyp controlled by more
as genes on normal ypic Answer: than one gene? [MODEL QUESO

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hdividal. it is character epistasis.
the same
is callai
ofallelic or nn-allele genes ot ne same allelic pair The sizes of all or these body
det
Gene
interaction is the
intiuerse where [wo
nonis, cases ntuence one another 1S
called geno skin, hair, and eye color are
parts are, in turn, determined
also polygenic traits
by numerous genes. Human
trait. ln xher than one allele at different loci. The because they are influenced by mor
Cpression of the ditfert allelic is
more result is the perception of continuous
or geaes of two or the expression of these traits. gradation in
interaction. [MODEL QUSTION]
Interaction? 14. What is Epistasis?
Complementary Gene
10. What is genes of [MODEL QUESTION]
is the production
by twO Interacting Answer:
Answer:
Complementary Gene lnteraction Epistasis Is the phenomenon where the effect of one
The either one separately. presence of one or more 'modifier genes', i.e.
gene (locus) is dependent on the
those praducad by
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effects distinct from the genetic background.Originally the
[MODEL QUESTION] term meant that the phenotypic effect of one gene
is masked by a different gene
11. Give example of
supplementary Gene. (locus).I Thus, epistatic mutations have different effects in combination than individually.
own effects It was originally a concept from genetics but is now used in biochemistry,
Answer: are able to produce their computational
genes which not only form a new
They are two non allelic state but can also interact to
biology and evolutionary biology. It arises due to interactions, either between genes, or
prasent in the dominant
independently when
example of collaborative
supplementary genes, P and within them, leading to non-linear effects. Epistasis has a large influence on the shape
trait. Comb types in pouliy is an of evolutionary landscapes, which leads to profound consequences
R for evolution and evolvability of phenotypic traits.
Give example.
12. Define "polygene" or "multiple gene inheritance". [MODEL QUESTION 15. Define CELL CYCLE. [MODEL QUESTION]
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Answer:
Answer a group of non- Cell division is a very important process in all living organisms. During the division of a
A "polygene" or "multiple gene inheritance" is a member of
epistatic yenes that interact additively to influence a phenotypic trait. The
term cell, DNA replication and cell growth also take place. All these prOcesses. i.e. cell
monozy go0us is usually used to refer to a hypothetical gene as it is often difficult to division, DN replication, and cell growth, hence. have to take place in a coordinated
characternse the effect of an individual gene from the effects of other genes and the
way to ensure correct division and formation of progeny cells containing intact genomes.
environment on a paricular phenorype. Advances in statistical methodology and high The sequence of events by which a cell duplicates its genome, synthesises the other
throughput sequencing are. however, allowing researchers to locate candidate genes fo constituents of the cell and eventually divides into two daughter cells is termed cell cycle.
process, DNA
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the trast. In the case that such a gene is identified, it is referred to as a quantitative trait Although cell growth (in terms of cytoplasmic increase) is a continuous
The replicated.
locnsQTL). These genes are generally pleiotropic as well. The genes that contribute to synthesis occurs only during one specific stage in the cell cycle.
pe 2 diabetes are thought to be mostly polygenes. In July 2016. scientists reported chromosomes (DNA) are then distributed to daughter nuclei.by a complex series of
genetic control.
Identitying a set of 355 genes from the last universal common ancestor (LUCA) o events during cell division. These events are themselves under
all organisms living on Earth.
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Cell Cycle. [MODEL QUESTION]

Traits with polygenic determinism correspond to the classical 16. Describe the different Phases of
quantitative characters, a
opposed to the qualitative characters with monogenic Answer:
or oligogenic determinisn is illustrated by human cells in culture. These cells divide
essence instead of two options, such as freckles or no freckles, A typical eukaryotic cell cycle
there are many variatio1. this duration of cell cycl can vary from
Like the color of skin, hair, or even eyes. once in approximately every 24 hours. However, to
type cell type. Yeast for example, 'can
organism to organism and also from cell
90 minutes. The cell cycle is divided into
progress through the cell cycle in oniy about
two basic phases:
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Prophase which is theCf
rst
the S and yz pnasCs the new of nitosis follows the S and

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Interpase DNA molecules G2 phases of interphase.
Phase (Mitosis phase)
[MODEL QUESTION] rophase 1S marked formed are n
by
chromosonal material the initiation of condensation not distinct but intertwined.
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of cet cycte becomes untangled of chromosomal materia.

17.Describe the InterPhase The centriole, which had undergone during the process
of chromatin condensation.
ph.iSCS move towards oppoSite duplication during
Answer: S phase of interphase, now
into thre fut/her poles of the cell. begins
ne nterphase is divided marked by the following
characteristic
The completion
of prophase can
phase (Giap 1) thus be

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Gl events:
phase (S nthesis)
I Chromosomal material condenses
S
Chromosomes are seen to be to form compact mitotic
composed of two chromatids chromosomes.
G2 phase (Giap )
DNA replication
n. the centromere. attached together at
and iniliation ol
interval between mitosis grows but does not Initiation of the assembly
coresponds to the continuously of mitotic spindle, the microtubules,
o phase metabvlically active and
components of the cell the proteinaceous
cell
during which DNA synthesis or
is
During GI phase the cytoplasm
phase marks the period Cells at the end of prophase, when help in the process.
replicate its DNA. S or synthesis DNA per cell doubles. If the viewed under the microscope,
place. During this time the amount of complexes, endoplasmic reticulum, do not show goigi
replicatien takes u "cases to 4C. However, there is no nucleolus and the nuclear envelope.
DN.A is denstai as 20 then il
Initial amount of or 2n number of
number. if the celi had diploid
increase in the chromseme
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ol chromosomes remains the same,
Metaphase
chromosomes at Gi . esen arter S phase the number The complete disintegration of the nuclear
replication begins in the nucleus, and envelope marks the start of the second phase
i.e. 2n. In anima! cells., during the S phase, DNA of mitosis, hence the chromosomes
are synthesised are spread through the cytoplasm of the cell.
the centriole duplicates in the cy1oplasm. During the G2 phase, proteins stage, condensation of chromosomes is completed By this
in preparation for mitosis w hile cell growth continues. and they can be observed clearly under
the microscope. This then, is the stage at which
Some cellsin the aduit animals do not appear to exhibit division (e.g.. heart cells) and morphology of chromosomes is most
easily studied. At this stage, metaphase chromosome is
many other cells divide only occasionally. as needed to replace cells that have been lost made up of two sister chromatids,
because of injury or cell death. These cells that do not divide further exit Gl phase to
which are held together by the centromere. Simall disc-shaped
structures at the surface of
the centromeres are called kinetochores. These
enter an inactive stage called quiescent stage (G0 ) of the cell cycle. Cells in this stage structures serve as the sites of attachment
of spindle fibres (formed by the spindle fibres) to the chromosomes
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emain metabolically ative bur no longer proliferate unless called on to do so depending that are moved into
on the requirement of he organism. position at the centre of the cell. Hence, the metaphase is characterised
by all the
In animals. mitotic cell division is only
seen in the diploid somatic cells. Against this, the chromosomes coming to lie at the equator with one chroimatid of each chromosome
plants can show mitotic divisions in both
haploid and diploid cells. From your
connected by its kinetochore to spindle fibres from one pole and its sister chromatid
recollection of examples of alternation
of generations in plants identify plant connected by its kinetochore to spindle fibres from the opposite pole. The plane of
stages at which mitosis is seen in haploid species and alignment of the chromosomes at metaphase is referred to as. the metaphase plate. The
cells.
key features of metaphase are:
18. Describe M PHASE
in detail. Spindle fibres attach to kinetochores of chromosomes.
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AnSwer: [MODEL QUESTION]

This is the most dramatic period Chromosomes are moved to spindle equator and get aligned along metaphase
virtually all components
of the cell cycle, involving plate through spindle fibres to both poles.
a major reorganisation
progeny cells is the same,
of the cell. Since the number
of chromosomes in the parent ana
o
it isalso called as equational Anaphe(1se
mitosis has been divided division. Though for
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understand that cell

into four stages
of nuclear division, convenienc At the onset of anaphase. each chromosome arranged at the metaphase plate is split
division is a progressive it is very essentia
drawn between various process and very Simultaneously and the two daughter chromatids, now referred to as chromosomes of the
stages. Mitosis is
divided into the clear-cut lines cannor future daughter nuclei. begin their migration tovards, the two opposite poles. As each
Prophase following four stages:
Metaphase chromosome moves away from the equatorial plate, the centromerc. of each chromosome
is towards the pole and hence at the leading edge, with the arms of the chromosome
Anaphase trailing behind. Thus, anaphase stage is characterised by the following key events:
Telophase
Centromeres split and chromatids separate.

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pores Answer:

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opposite [MODEL QUESTION]
Chromatids move to chromosoes
chromosomes tha
that have The production of oflspring by sexual
teloplhase, the with a complete repr
individuality. The individual ch with
each complcte haploid set of chro ncudes fusion of iwo gametes,
of chromosomes. Gametes the
mitosis, i.e.. diploid cells. his specialised
lose their tends to collect in a. mass i
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Telophase stage of and kind of cell division are formed from specialised
tinal decondense
At Deginning
roa
of the
respective poles chromatin
material followin wing key events: half results in the production of haploid that reduces the chromosome
daughter cells. This number
reached heir be seen
and which shows the identity is
is lost as meiosis. Meiosis ensures the production kind of division
is caliea
longer stage their of haploid phase

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mes can no This is the and eproducing organisms whereas fertilisation in the life cycle
of sexually
the ta poles(Figure 10.2 d). spindle poles restores the diploid phase. We come across
( opposite meiosis duiring gametogenesis in plants
hromosomes cluster at
the two and
chromosome clusters. haploid gametes. he key features meiosis animals. This leads to the formation ot
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of are as follows:
discrete elements. assembles around the
envelope reform. MeiosIs involves two sequential cycles of nuclear and cell division
Nuclear complex and ER and meiosis lI but only a single cycle of DNA replication. called meiosis
Nucleolus. golgi [MODEL QUESTION]
Meiosis I is initiated after the parental chromosomes
have replicated to produce
identical siter chromatids at the S phase.
Cytokinesis. into daughter
19. Define duplicated chroinosomes separate Meiosis involves pairing of homol:us chromosomes and
Answer: segregation of daughter cells by a recombination
not only the divi1ded into two between them.
Mitosis accomplishes
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cel
(karyokinesis). but the
cell itself is
division is complete. In an animal . Four haploid cells are formed at the end of meiosis I.
nuclei
cytokinesis at the end of
which cell
plasma membrane. The furro
process called a furrow in the
the appearance of cell cytoplasm into two.
this is achieved by ultimately joins in the centre dividing the 22. Mention the significance of meiosis. [MODEL QUESTION]
gradually deepens and inextensible cell wall, thererfore they Answer:
a relatively
Plant cells however.
are enclosed by
In plant cells, wall
formation starts in the Meiosis is the mechanism by which conservation of specific chromosome number of each
different mechanism. The formation of
undergo cytokinesis by a existing lateral wals. species is achieved across generations in sexually reproducing organisms, even though
grows outward to meet the precursor, called the cell-plate
centre of the cell and a simple the process, per se, paradoxically, res ults in reduction of chromosome number by half. I
begins with the formation of time of
the new cell wall two adjacent cells. At the also increases the genetic variability in the population of organisms from one generation
lamella between the walls of
that represents the middle get disributed between
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mitochondria and plastids to the next. Variations are very important for the process of evolution.
cytoplasmic division, organelles Iike followed by cytokinesis as
organisms karyokinesis is not
the two daughter cells. In some leading to the formation of syncytium. 23. What is Gene mapping? [MODEL QUESTION]
which multinucieate condition arises
a result of Answer: on a
[MODEL QUESTION] Gene mapping is the sequential allocation of loci to a relative position
20. What is Significance of Mitosis? markerS
chromosome. Genetic maps are species-specific and comprised of genomic
Answer:
diploid cells only. However, and/or genes and the genetic distance between each marker.
Mitosis or the equational division is usually restricted to the
divide by mitosis. It is
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in some lower plants and in some social insects haploid cells alsó
24. What are the differences between Mitosis versus Meiosis? [MODEL QUESTION]
very essential to understand the significance of this division in the life of an organism.
Are you aware of some examples where you- have studied about haploid
and diplo
Answer:
insects? Mitosis usualy results in the production of diploid daughter cells with identicat ways, mitosis and meiosis. Mitosis results in two
Cells divide and reproduce in two
genetic complement The growth of multicellular organisms is due to mitosis.e four sex cells. Below we highlight the
Identical daughter cells, whereas meiosis results in
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growth results in disturbing the ratio between the nucleus and the cytoplasm. It thereo between the two types of cell division.
Keys ditferences and similarities
becomes essential for the cell to divide to restore the nucleo-cytoplasmic ratio. A
significant contribution of mitosis is cell repair. The cells of the úpper layer ot
epidermis, cells of the, lining of the gut, and blood cells are being constantuy rpelt Differences Meiosis_
Mitosis nvolves two successive cell divisions
Mitotic divisions in the meristematíc tissues the apical and the lateral cambium,
i Involves one cell division Results in four daughter cells
in a continuous growth of plats throughout their life. Results in two daughter cells Results in haploid? daughter cells
Results
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Nialved
is alleles of a gene pair in the recessiverecessive is applied both to tle organism
(chnimosOme nunOer condition and to having
masked by another allele of thesame gene. the allele ihose effect can be

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itosis(chronosome' number | rcnt cel
daughter cells"
n diplod gcnelcalyY dilferent
renmains tie same
as parent celn
Daughter cells are fungi 27. What is Dominance in genetics?
Occurs only in
anin:alS. PlanS nd Answer: [MODEL QUESTION]
are genetically tdcnttcl sperm) ,only
Dughter cells germ Ceis (EES and Dominance, in genetics, is the phenomenon
\inis tronm|Cre:alcs
ccurs in all organisins exCpt apart a chromosome masKing or overriding the effect
of one variant (altle) of a gene on
cells (somatic?)

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all body of a different variantof the same gene
rEaes and spen on the other copy or the chromosome.The first variant is
the erm cells" (egs takes much longer
ProphaselrecomoinallioncroSSing second recessive. Ihis state of having two different variants termed ominant and the
of
over o of the sime gene on each
Propnase Is muctt shotcr occurs 1nnvoives I chromosome is originally caused by a mutation in one of the genes,
revOmbination crossing
over chromosomes in prophase eiter
new (de novo)
or inherited. The terms autosomal dominant or
autosomal recesive are used to
prophase Chronmosomes line describe gene variants on non-sex chromosomes (autosomes) and theivassociated traits,
metapnase Ipars or
individual chromosomes (pairs of In equator. while those on seX chromosomes (allosomes) are termed X-linked dminant, X-linked
In merapnise up along the
eyuator the SIster chromatids recessive or Y-|inked, and these show a very different inheritance and presentation
During anapnase
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chrumattdS) line uP alony the

sister chromatids are| move together to the same pole. pattern to autosomal traits which depends on the sex of the individual. Aditionally, there
During 3i12phse the chromatids
During anaphase Il the sister are other forms of dominance such as incomplete dominance, in whih a gene variant
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Separated to OFposite poles.
are separated to oppoSite poles. has a partial effect compared to when it is present on both chromsomes, and co-
dominance, in which different variants on each chromosome both shov their associated
[MODEL QUESTION] traits.
of Mitosis versus meiosis?
25. What are the Similarities
Answer:
Mitosis
Diploid parent cell
and telophase
Consists of inierphase. prophase. metaphase, anaphase
In metaphase individual chromosomes (pairs of chromatids)
line up along the
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equator.
During anaphase the sister chromatids are separated to opposite poles.
Ends with eytokinesis.
Meiosis
Diploid parent cell
Consists of interphase. prophase, metaphase, anaphase and telophase (but twice
In metaphase II individual chromosomes (pairs of chromatids) line up along tne
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equator.
During anaphase Il the sister chromatids are separated to opposite poles.
Ends with cytokinesis.
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26. WhatsRecessiveness in genetics? [MODEL QUESTION

Answer:
Recessiveness. in genciics, the, failure of one pair of genes (alleles) prese n an
individual to express itself in an observable of a luence, or
manner because of the greaer
dominance. of its opposteacting
partner. aherited
characteristic. but the presence otthe recessíve Both alleles affect the same atioll
gene cannot be determined by
of the organism; i.e., althougn present in the organism's oDsait is
genotype. the recessic BIO-65
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(1) Terin Iipid was coined by Bloor.
(2) These arc esters
aY 1 latty acids and alcohol.
They are hyurophobiC insoluble
in water
(4) Lipids are classilied into three groups:- but soluble in benzene, ether and chloroform.
A) Simple lipids: These are the esters
of fatty acids and glycerol.
Chapter a a Glance (a) Fats and Ous: (Natural Again they are typed as:

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lipids or true fats). These.
Pats which are liquid at room are triglycerides of fatty
acid and giycero.
temperature are called
called polyunsaturated e.g. suntlower oil, oils. Oils with polyunsaturated tatty acids are
cellulosSe. lower blood cholesterol.
stanch and
Carbohydrates:
glyavfn (animal starch), plant eNists only' in To but constitutes 80% bf (b) Fatty acids: Obtained by hydrolysis
of fats. Formi acid is simplest fatty acid
Csugas.of carbo nthesis. It
drate: Mainy phutrsy These are of 2 types:- (HCO0H).
ource in the ratio Cn2N. It is also called
6) Saturated 1atty acids: The fatty acids which do not have double
dry weight of plats.
the hydrogen and oxygen bond in between carbon
Compositivn: lt onsists of cartvn. atoms.e.g. butyric aCId, palmitic acid, hexanoic acid, etc. They
aYInNVieNs. have high melting points. solid at
SICchartde and sugar are their basic room temperature and increase blood cholesterol.
Candydrates (ii) Unsaturated fatty acids: The fatty acids which have double bonds
in carbon atoms. e.g. 8
hexadecanoic acid, 9 octadecanoic acid etc. They have lower melting points mostly found plant
in
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fats, liquid at room temperature and lower the blóod cholesterol.
Polysaccharides (number of (c) Waxes: These are simple lipids composed of one molecule of long chain.fatty acid and long
(number ot
Monosxehurdes and As 10 monosaccharides over T0) chain monohydric alcoho. Waxes have high melting point, insoluble in water, resistant to
their éerv aves
L teasachandes etc.) atmospheric Oxidation, chemically inert and not digested by enzymes. They reduce rate of
transpiration by makings plant tissue water proof arnd work as excellent lubricant.
(B) Compound lipids: They: contain some additional or element. Group' with fatty acid and
alcohol on the basis of group they may be of following types:
(a) Phospholipids: These contain phosphorie acid. it helps in transport, metabolism., blood
Denaaves of Homopolysaccharides Heteropolysaccharides
furosaetartes clotting and permeabilityý of cell membrane. It is a bipolar molecule i.e. phosphate containing end
locosacchardes, (starch. amylopectin. (glycoproteins, starch. 1S hydrophiliç whereas fatty acid molecules represent hydrophobic (non-polar tail).
Trmose C. Tetrose -CC
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gycogen, cellulose etc.)

Pertuse-. Hexuse £
proteins)
(6) Glycolipids: These contain nitrogen and carbohydrate beside fatty acids. Generally. found in
teptase-C.Octoses-C white matter of nervous system. e.g. sesocine frenocin.
(c) Chromolipids : It includes pigmented lipids eg carotene.
andses .DecoSes IUC

with fatty acid

(d) Aminolipids : Also known as sulpholipids. contains sulphur and amino acids
It

lipids resistant to water, and also provide

and giycerol. Cutin and suberin are also compound
Glycosides e.g. mechanical support in plants.
eg of simple and compound lipids.
(ii) Derived lipids: These ar obtained by hydrolysis
ArOIe acads Annosaccharndes Phosphosaccharides
Ure acds eg
Eycouronc acad, grucaroic acd g ghcosamine,. e.gglucose -6- nucleotides,
nucleosidcs. (5) Functions of lipids
galactosamine phosphate, fructose 1,6 more energy in the cell than protein and
(a) Oxidation of lipids yields comparatively
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biphosphate etc. Coenzymes etc. 39.1 KJ.

4}Properties of nnosaccharide onydrates. Igm of lipids accounts for to embryo
(a) Monosaccharide are colourless. sweet tasting, solids (D) The oil seeds such as groundnut,
mustard, coconut store fats fo provide nourishment
(b) Due to asymmric carbon. they
exist in different isomeric forms. They can rotate polari giring germination. the membrane systems of the cell are made up of
light hence they ardextrorotatory and leavorotatory.
They function as structural constituent i.e. all
(c) D-glucose aftereduction gives rise to a lipoproteins.
mixture of polyhydroxy alcohol, sorbitol or mannito
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(d) The sugars wn a free aldehyde emulsifier.

or ketone group reduce Cu" to
(e) Sugars show Kidatiorn, sterification and Cu' (cupric to cuprous) ) Amphipathic lipids are
fermentation. (e) It works as heat insulator.
() The aldehy der ketone group of homiones.
ofa simple sugar can join an alcoholic
group of another
() Used in synthesis
vitamins A, D, E, and K.
compound bond-9-C the process involves loss
H+OH- H:O.
of water and is called condensation (H-0°7 Oo 6 ats provide solubility to

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amuo acnd). prokar otes NuCnition: Nucleic, acids are the polymers
prvtems (called
universSil in
virUses.
and (1) of nucleotide made up of carbon,
components ot
vell nitrogen and phosphorus and
which controls the basic functions hyaroge
nt
Amino Acids
ds are normal spevitiad ki
genetic code
and made
up of
o
Ox
e were first reported by Friedrich
(2)Thes Miescher (1871) from
of the cell.
011) Irom the nucleus of pus pus cell.
are
T
eukaryoteS
20 in
number
acids are
basic units oI
Composition: Aminoonganic acids with a
Structure and S. Amino acids arr Carboxyl group
prorein
carboxyl group
attributes acidic
(-COOH
properties andOne
maintain pH
amino
TYpes
nucleic acid
/3) Altmann called it first time as
(3) Are found in nucleus. They help in transfer
of genetic informátion.
cell.

of nucleic acids :On the basis of nucleotides i.e. sugars,. phosphates and nitrogenous
nelp-to maintain

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sometimes pH. General
nd group(-NH:) on the a arbon atom. serve as
buffers and nucleic acids are of two ypes which are further subdivided. These are DNA
they
Jmind In solution. Deoxyribonucieic acia) and RNA (Ribonucleic
nucleic acid),
u gives
basic otes. (Deoxyribonycleic acides)
formula is
R-CHNH:COOH (A) DNA
Classification Types of DNA: It may be linear or circular in eukaryotes and prokaryotes respectiveiy.
(4)
e.g glycine,'alani ne (a) Palindromic DNA: Ihe DNA helical bears nucleotide in a serial arrangement but oPposite in

Based on R-group ofamino

acids group in the side Cnan. two strands
no functional
(a) Simple amino
acids: These have T-T-A-A-C-G-T-T-A-A..
serine, etc
leucine. valine ets. alcohol group in side
chain. eg. threonine, -A-A-T-T-G-C-A-A-T-T..
acids: They have cnain. e.g. methionina
onine,
(6) Hydroy amino sulphur atom in siae (b) Repetitrve DNA: IhiS type of arrangement is found near centromere of chromosome and is
amino acids: They have.
() Sulphur containing inert in RNA synthesis. The sequence of nitrogenous bases is repeated several times
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in side chain. e.g.
lysine, arginine. in' nature. They,are
Cstenine group (-NH;) (c) Satellite DNA: It may have base pairs up to 11-60bp and are repetitive
They have basic acid, glutamic acid
d) Basic amino acids: group in side chain. e.g. aspartic
is deutrorotatory and
They have carboxyl group, onee of used in DNA matching or finger printing (Jefferey). In eukáryotes, DNA
(e) Acidic amino acids: amino acids. In this sugars have pyranoOse configuration.
acids:-These are the derivatives ot acidic
() Acid amide amino e.g. aspafagine, glutamine. is second type of nucleic acid which is found in nucleus as
converted to amide (-CONHh). (B) RNA or Ribonucleic acid: 'RNA
the carboxyl group kas been the side chain includes a ring carry the genetic information
These are the amino acids in which well as in cytoplasm 1,e. mitochondria, plastids, ribosomes etc. They
(g) Heterocy clic amino acids: in the cell.
e.g. tryptophan, histidine. in some Viruses. hey are wIdely distributed
I

ene atom other than carbon.

Invoiving least
at chain. e.g.
(a) Aromatic amino acids: They have
aromatic group (benzene ring) in the side
phenylaanine. tyrosine etc. Multiple Choice Type Questions
converting fats into
M

Nucleotides:
Some of enzymes, which are associated
the in [MODEL QUESTION]
) Structurally a nucleotide can be regarded as a phosphoester of a nucleoside.
1.

)A combination of nitrogens base and a sugar is called nucleoside and combination of a base,
a carbohydrates, are present in b) Golgi bodies
a) Liposomes
Sugar and phosphate group is known as nucleotide. d) Glyoxysomes
c) Microsome
Types of nitrogen base Nucleoside Nucleotide Answer: (d)
Adenine [MODEL QUESTION]

.
Adenylic acid are
Largest physical and chemical molecules
Adenosine
|
2. b) Lipidss
Guanine Guanosine Guanylic acid a) Carbohydrates d) Nucleic acids
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|
Cytosine Cytidine Cytidilic acid c) Proteins
Thymine Thymidine Answer: (C)
Thymidylic acid.
Lracil Uridine Uridylic acid [MODEL QUESTIONJ]
3. No cell could live without b) Enzymne
(3) Functions of nucleotides: a) Phytochrome
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Following are the major functions

of nucleotidees. a) Protein
(a) Formation of nncleic acids: Different nucleotides polymerize c) Chloroplasts
RNA. together to form DNA and Answer: (d)
(b) Formation of;enerzy
carrier: They characteristics of plants [MODEL QUESTION]
help in formation of ATP,
TDP,TTP. CDP, etc. which on
breaking release energy. AMP, ADP, GD 4. Which of the following is the b) Pyruvic acid and glucose
a) Glucose and cellulose
(c) Formation of Coenzymess
Coenzymes like NAD,
ormea, d) Starch and pyruvic acid
Coenzy mes are non-proteinaceos NADP, FMN, FAD, CoA,
substance necessary
for the activity
etc are T Cellulose and starch,
of the enzymes. Answer: (C)
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A5. A nucleoside differs from
PUBLICATIONSS a nucleotide
POPULAR
of many units
of a) Phosphate in not having

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[MODEL QUESTION)
compounds made [MODEL QUESTIOM c) Phosphate and sugar b) Sugar
cellulose are the Answer:(b) d) Nitrogen base
.otarch and
b) Fatty acid
sugar d) Amino acid
a) Simple 16. DNA was first discovered by
c Glycerol a) Beadle and Tatum MODEL QUESTIONJ
Answer:(a MODEL QUESTIONI b) Watson and Crick
c) Friedrich Miescher
6.

T.
Oval shaped and
Wheat
a)
Answer: (¢)
eccntric starch
Maize
b)

What are the most diversed

c)
Lipids
Carbohydrates
Answer: (b)
particles are found in
c) Potato

molecules in the cell

b) Proteins
d) Mineral salts

The fomm in which sugar is present.in sugarcane

d) Rice

[MODELQUESTION

[MODELQUESTIONI
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Answer: (6)

17. Which one of the following is a

a) Nitrous acid
c) 5-bromouracil
Answer: (c)
d) Kornberg

base analogue
b) Colchicine
d) Caffeine

18. Isolation and purification of specific DNA segment from a

achieved by
[MODEL QUESTIONJ

living organism was

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8. [MODEL QUESTION]
a) Maltose b) Sucrose c) Fructosse d) Glucose a) Crick b) Nirenberg
Answer: (d) c) Khorana d) Beckwith and his colleagues
Answer: (6)
9.Peptide bond is fomed between two amino acids through [MODEL QUESTIONI
a) Addition of water b) Loss of water
. 19. Cyclic adenosine monophosphate was discovered by [MODEL QUESTION]
c) Decarboxylation d) Deamination a) Bekhor et al b) E.W. Sutherland
Answer: (d) c) Beerman d) Weismann
Answer: (6)
10. A basic aminoacid is [MODEL QUESTION]
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a) Leucine b) Methionine [MODEL QUESTION]

c) Aspartic acid
20. Clover leaf model of tRNA has
Answer: (6)
d) Lysine a) Acceptor arm and C arm b) Anticodon arm
C)D arm d) All the above
11. Most abundant Answer: (d).
organic compound on earth is
a) Cellulose [MODEL QUESTION
b) Proteinn c) Lipids 21. Micrococcas nucilease enzyme [MODEL QUESTION]
Answer: (c) d) Steriods
a) Cuts the DNA from a specific site
12. Most common b) Joins the DNA segment
monosaccharides found c) Cuts the DNA at the junction between nucleosome
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a) irioses in nucleus are

Answer: (B}
b) Tetroses [MODEL QUESTION) d) Binds the DNA with histone
c) Pentoses d) Hexoses Answer: (C)
13. Hydrolysis
of nucleic acid yields DNA double helix is [MODEL QUESTION]
a) Only sugar 22. The mean diameter of
[MODEL QUESTION b) 3.4 A° c) 4.5 A d) 10 A°
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c) Ntrogenous b) Phosphoric a) 20A

Answer: (c) base only d) All of the acid onlyabove Answer: (a)
14. Nucleic at 82-90oC, then [MODEL QUESTION]
acidswere discovered 23. If an isolated strain of DNA is kept
dwatson and ch vered by RNA b)It divides into one million pieces
c) Wilkins ick a)it changes into d) It uncoils into helixes
b) Khorana [MODEL QUESTION c) No effect
Answer: (c) d) Miescher Answer: (d)
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d) 34 A° d) Both (a)
A Answer: (a) and (b}
24. The length of a helix of DNA
IS
c) 30

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b) 20 A
a) 10A 3. Which one of the following is
not a process of
Answer: (d) m-RNA molecule DNA replication
bonds to a [MODEL QUESTION
molecule hydrogen a) Palindromic [MODEL QUESTION]
*Ich site of a t-RNA c) Conservative
b) Dispersive
b) Anticodon molecule d) Semiconservative
a) Codon d) 3¢ end of the
t-RNA Answer: (a).

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molecule
c) S¢ end of the t-RNA
Answer: (6)
[MODEL QUESTION] Short & Long Answer Type
Questions
are known
Z6. How many types of ribonucleic acids b) Two types
a) One type 1. What are the molecules of life?
d) Four types [MODEL QUESTION]
c) Three types Answer:
Answer: (Cc) All life on Earth is built from four different types of molecules. These four types of
[MODEL QUESTION] molecules are often referred to as the molecules of life.
27. The element absent in RNA is The four.molecules of life are proteins, carbohydrates, lipids and nucleic acids. Each of
b) Sulpher c) Oxygen d) Hydrogen
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a) Nitrogen
the four groups is vital for every single organism on Earth. Without any of these four
Answer: (b)
molecules, a cell and organism would not be able to live. All of the four molecules of life
28. Who was awarded Nobel Prize for synthesis of RNA in 1959 are important either structurally or functionally for cells and, in most cases, they are
[MODELQUESTION] important in both ways.
a) S. Ochoa b) A. Kornberg
c) H. Khorana d) Nirenberg 2. What are the four molecules of life? [MODEL QUESTION]
Answer: (2) Answer:
All organisms need four types of organic molecules: nucleic acids, proteins,
29. Breakthrough of the year 2002
carbohydrates and lipids; Iife cannot exist if any of these molecules are missing.
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a) cDNA [MODEL QUESTION]

c) rDNA
b) 16 SrRNA
d) miRNA
Nucleic Acids. The nucleic acids are DNA and RNA, or deoxyribonucleic acid
Answer: (d) and ribonucleic acid, respectively..
Proteins...
30. Uridine monophosphate
is found in Carbohydrates. ..
a) Centrosome [MODEL QUESTION]
b) Lysospme Lipids
Answer: (d) c) Cell wal d) RNA
[MODEL QUESTION]
molecules living things?
3. Are
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31. Franklin and Wilkins

a) Contains four
showed that DNA . Answer: a lot of hydrogen, oxygen, nitrogen,
bases
c) Has equal amount b) Is a helix
[MODEL QUESTIONI But as well as carbon, living organisms also contain
to form complex molecules of
d) Is made up of of adenine and
thymine sulfur, and phosphorous. Those atoms combine together
nucleotides lipids, and nucleic acids
Answer: (b) various types: proteins, carbohydrates,
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molecule of life? [MODEL QUESTION]

32. Feulgen reaction
is a special 4. What was the first
) RNA
b)DNA test for Answer: RNA, found in all living cells, would
The widely accepted view among Scientists that hypothesizing an "RNA-first" view
[MODEL QUESTION] isS
Answer: (b) c) Protein
of lite, of
d) Carbohydrate have likely represented the first moleeules
34. In which from non-living molecules.
type of DNA
replcation the origin of living systems
purely a new one of the two newly
and
a) Conservative the other oneis old formed molecules one s
b) Semiconservative MODEL QUESTIONJ
. Why is carbon so basic to life? [MODEL QUESTION]

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Swer:
POPULARPUBLICATIONS Ansher of carbon ato
number of atoms present is

TI
hents, includin If Glucose, 6, then it is known
with any eiemenUs, including itself,
arge and
Example: a Hexose Sugar. Fo
form stable
bonds of very
Answer: ability to nuge varietycarbon-based comn
ne reasin is carbon's carbon to fornia, lion
million earbon-based compounds
allows nearly t0
his property fact ther ar*
ln
omplex molecules. H-C OH

AU
in living things! [MODEL QUESTIONI
HO- C- H

6.What is macromolecule?
as protein, commonly created' by
Answer:
A macromolecule is
a very
large molecule, such
subunits (monomers). Iney are
typically composed e H-C- OH
smaller common
the polymerization of The most macromolecules
thousands of atoms or
more.
proteins, carbohydrates and
lipids) and CHOH
are biopolymers (nucleic acids,
in biochemistry as lipids and macrocycles). Synthetic Fig: Structure of Glucose or Hexose Sugar
non-polymeric molecules (such
large and synthetic Tibers as well as experimental
macromolecules include common plastics If number. of 'carbon atoms present is 5, then it is known as Pentose Sugar. For
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materials such as carbon nanotubes. Example: Ribose.
[MODEL QUESTION
7. Give the Definition of Carbohydrates.
Answer:
Carbohy drates are made up of carbon, hydrogen, and oxygen. They can also be defined H=C--OH
as Pplyhydrory Aldehydes or Ketones.
H-C OH
8. Describe the Carbohydrate Structure. MODEL QUESTION] H-C-OH
Answer:
H-C -H
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Generally wrd saccharides are used for carbohydrates. Saccharides includes.

starch,
sugars, cellulose etc. Formaldehyde is considered as simplest carbohydrate. OH
They have
general formula (CH:O), where n is three or more. They
have aldehyde or ketone. with Fig: Structure of Ribose
hydrogen atom and hydroxyl group.
If number .öf carbon atoms present is 3, then it is known, as Triose Sugar. For
Example: Glyceraldehyde.
CH,OH c.
H-C-OH
H-C-OH
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=0 H

HO-C H HO-C
HO-C - H
HO-C- H
H-C OH HO H
CH:OH

H-C O H-C-OH Fig: Structure of Glyceraldehyde

H-C- OH
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CHOH H-C- OH
of Carbohydrates? MODEL QUESTION]
Glucose
CHOI
CHOH 0.What are the different classes
Galactose Answer: Carbolydrates
Fructose lassification of Carbohydrates /Types of
of units of sugar
9. Classify the
E Structure of Carbohydrates Classification on the basis of number
Monosaccharideson Saccharides can be
the Basis of Number
of Carbons sen t. monosaccharides,
[MODEL QUESTION BIO-75.
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POPULAR acids: Obtained by hydrolysis
(HCOOH). These are of 2 types: of fats. Fomic acid
is simplest raty a d
disaccharides. Saturated fatty acids: The fatty

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NlonosSaccharidee acids which do not
oligosaceharides and known as s between carbon atoms.e.g. butyric have double bond in
saceharides. sacchariudes ac bond, thecy acid, palmitic acid, hexanoic
glycosidic
Rly saccharide or unit of ane joimed by Glucose and Fruch
uctose.
They have high melting points,
solid at room temperature and
acid, ele
Ihe siplest monosaccharides composed of cholesterol. increase Dioou
When tuo Suenose. Sucrose is Oigosaccharidas
ltose.Disaccharides, such as are joincd, they'
Torm Such Unsaturated fatty acids: The fatty acids which have
.

form
of
monosaccharides monosaccnarides are joinedd, they atoms. e.g nexadecanoic acid, 9 double bønds incarbon
When 2 to 10 units

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10 octadecanoic acid etc. They have lower
more than
Raftinose. When etc. melting points mostly found in plant fats, liquid at room temperature
as
Polysachharides. Such as
starch, celluloSe lower the blood cholesterol. and
torm Group Present:
Functional (c) Waxes: These are simple lipids composed of one molecule, of long. chain fatty
Monosaccharides on the Basis of (MODEL QUESTION
11. Classify the acid and long chain monohydric alcohol. Waxes have high melting point,
insoluble in water, resistant to atmospheric oxidation, chemically inert and not
Galactose;. Rihn.
Answer For Example: Glucose, digested by enzymes. They reduce rate of transpiration by making plant tissue
Aldoses contain the aldehyde group.
water proof and work as excellent lubricant.
Glyceraldehyde. etc.
For Example: Fructose Types of waxes
Ketoses contain the ketone group.
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group. For. Example: Glucose Plant wax: Forms coating.
sugars contain a hemiacetal or hemiketal
Reducing Bee's wax : t is secretion of abdominal glands of worker honeybee. It consists
Galactose. Fructose. AMaltose, Lactose
groups. For Example: Sucrose and al of palmitic acid and myricyl alcohol.
Non-reducing contain no hemiacetal
polysaccharides are non-reducing sugars. Lanolin or Wool fat: It is secreted by cutaneous glands, also obtained from
wool of sheeps. it consists of palmitic acid, oleic or stearic acid and
12. State the Functions of Carbohydrates. [MODELQUESTION cholesterol.
Sebum : It is secretion of sebaceous gland of skin.
Answer:
Functions are .Paraffin wax Obtained from petrolium.
:
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It isthe most common source of energy.

or element. Group with fatty acid
Cellulose is present in cell wall of plants that provides and rigidity to it (ii) Compound lipids: They, contain some additional
Lactose sugar is found in milk. and alcohol on the basis of group they may be of following types:
It helps in transport, metabolism,
Chitin is also another sugar found in exoskeleton of insects. a) Phospholipids: These contain phosphoric acid.
It is a bipolar molecule i.e.
It is a dietary fiber. blood clotting and permeability of cell membrane.
molecules represent
phosphate containing end is hydrophilic whereas fatty acid
13. What is Lipids?
[MODEL QUESTION hydrophobic (non-polar tail): Phospholipids' again comprises.
in ether and alcohol but insoluble in
Answer: Lecithin: These are yellowish grey solids, soluble
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em phosphoric acid and choline.

lipid was coined by Bloor. These are
esters of fatty acids and alcohol. a acetone, On hydrolysis they yield glycerol, fatty acid,
hydrophobic insoluble in water Tney
to lysolecithin. The enzyme is found in
but soluble in benzene,
ether and chloroform. Lecithins are broken down by enzyme lecithinase
venom of bee and cobra.
14. What are the different soyabean o. Cephalin contains choline
types of Lipid? [MODEL QUESTION Cephalins: Found in animal tissue and linoelic and arachidonic acid.
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Answer:
Lipids are classified or serine sometimes and stearic acid, oleic acid, fatty acids.
into three groups: nitrogen and carbohydrate beside
(i) Sinmple lipids: Theseare b) Glycolipids: These contain or nervous system, e.g. sesocine frenocin.
the esters of fatty acids and white matter
(a) Pats and Ois:(Natural yped
as Generally found in
glycerol. Again they
aic pigmented lipids e.g. carotene.
c) Chromolipids: It includes
.

lipids or true fats). id and

as sutpholipids. It contains sulphur and amino acids
glycerol. Fats which are These triglycerides a
liquid O 'acid Also known
at room oils w d) Aminolipids: resistant
polyunsaturated
faty:acids are called temperature are called oil 10we fatty acid and glycerol. Cutin and suberin are also compound lipids
polyunsaturated with
blood cholesterol. e.g. suntiow Oll, also provide mechanical support in plants.
to water and

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hydrolysis vf'
obtained by BIOLOGY
These are are om 17. Describe the Structure and Composition

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(ii) Derived lipids: following componens are called sterols. They of amino acid. [MODEL
Derived lipids include
withut straight chains
hydrocarh0n side chaun. Best knoi stérol
is
of Answer:
Anino acids are basic units oft
QUESTION]
Lipids protein and made
aSterols:hydrarbon rings and a coNLentration in nervous tissue and
long
bile Amino acids are organic up of C, H, O, N and sometimes
fused high progesterone, testoe acids with a carboxyl group S.
cholesterol. present in hormoneslike va LNH2) On the a -carbon (-COOH) and oneamino group
prcursor of alom. Carboxyl group
Cholesterol is also the
obtained firom gives ones. attributes acidic propertic amno
vitamin D. Diosgenin is group basic In solution, they
serve as buffers and help
and
and
.
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cortisol General formula is R-CHNH2,COOH. to maintain p.
estradiol and anti- infertility
pills.
(Dioscorea) usevi in making FoNglove (Digitalis
lantana) is a heart are
trom leaves of
Amino acids anmphoteric or bipolar ions or
prpannd other by peptide bond and long chains Zueitter ions. Amino acids link with each
() Digitalin: It is
stimulant. and yeast. It is
precursor of anosther are called polypeptide chains.
food. found in ergot
in
(c) Ergosterol: Present 18.What are the different Classes of amino acid?
ergocalciferol (D:). MODEL QUESTIONJ
form of vitamin D. as a result or the. reduction Answer:
in feces. It is formed
(d) Coprosterul: It is found cholesterol between Cs, and C. Classification
from the double bond of
bacteria in intestine o1ls o, camphor, eucalypts Based on R-group of amino acids:
oil and present mostly in
(e) Tarpens: lt is essential in
Phytol is a terpenoid alcohol present in Vitamin'A, K, E and (a) Sinmple unino acids: These have no functional group in the side chain. e.g glycine,
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lemon and mint.
are licopene, gibberellins and alanine, leucine, valine etc.
piyments like chlorophyll carotenoid. Other forms
(b) Hydroxy amino acids: They have alcohol group in side chain. e.g. threonine, serine,
natural uber.
derived from arachidonic acid. etc.
() Prostaglandin: lt is hormone ike compound
Mostly present in secretion of seminal vesicles in males and menstrual cycle
fluid (c) Sulphur containing amino acits: They have, sulphur atom in side chain. c.g.
,

methionine, cystenine.
in females.
(g) Blubber: A very thick layer of subcutaneous fat in whale. (d) Basic amino acids: They have basic group (-NH:) in side chain. e.g. lysine, arginine.
(e) Acidic anino acids: They have carboxyl group in side chain. e-g. aspartic acid,
15..What are the Functions of lipids? [MODEL QUESTION glutamic acid.
Answer: ) Acid amide amino acids: These are the derivatives of acidic amino acids. In this
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(a) Oxidation of lipids yields comparatively more energy in the cell than protein and group, one of the carboxyl group has becníconverted to amide (-CONH:). e.g. asparagine,
carbohydrates. I gm of lipids account for 39.1 KJ. glutamine. includes
tb) The oil seeds such as groundnut, mustard, coconut store fats to provide nourishment (8) Heterocyclic amino acids: These are the amino acids in which the side chain
histidine.
to embryo during germination. a ring involving' at least one atom other than carbon. e.g. tryptophan,
group (benzene ring) in the side chain.
(C) They function as structural constituent
i.e. all the membrane system of the cell are (n) Aromatic amino acids: They have aroniatic
made up of lipoproteins. C.g.phenylalanine, tyrosine, etc.
(d) Amphipathic lipids are emulsifier.
basis of the synthesis amino acids in body and
(e) It works as heat insulator. On the basis of requirements: On the
E

as:
() Used in synthesis of hormones. their requirement, they are categorized in body hence to be provided in diet
g) Fats provide solubility to vitamins A, D, E, (a) Essential amino acids: These are not synthesized
and K. isoleucine, theronine, lysine, etc.
Cg valine, leucine, Syntheized partially in the body but not at
the rate to
16 What is Amino Acid? (b) Semi-essential aminio ucids:
[MODEL QUESTION) e.g.. arginine and histidine.
Angwer: the requirement of individual.
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eet are derived from carbon skeleton of

Amimacids are normal components cell aculs: These amino acids
of proteins (called amino acid). They are in ( Non-essential aminn metabolism. In humans there are 12 non- essential
amino acids
numberspeciied in genetic code and universal ipids and carbohydrale acid etc. Prolne and
hydroxyproline have,
Otherw ise amino acids in viruses, prokaryotes
and yotes. e.g. alanine, aspartic acid, cysteine. glutamic are
eukayu called imino acids. Tyrosine can is
bee
may be termed rare amino NH: hence,
synthesis e.g. hydrOxyproline acids, which take part n rotein NH (imino group) instead of pigment melanin., Glycine
and non protein amino ein thyroxine and adrenaline and skin
synthesis e.g. Ornithin, nicotinamide
etc.
citrullin, gama-amínobutyric acids do not take part i"
acid (GABA) a neurotransmitter e. Converted into hormone
nccessary for production of heme.
Iryptopnan iS tne precursor of vitamin

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ano acnt l can
torm glucose n BIOLOGY
trom
yrvupis remoNed
lf anino tornms istnine.
amies c.g

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up Is remo'ed. it MODEL QUESTIONI
Amino Acid 7
Functions of
19. What ars the -c H-C
Answer:
Functions of Amino. Acids blecks of proteins and
enzymes.
)Amino acids are building

AU
foanm glucose.
(b By ghogenolysis they formed with the help of tyrosine.
adrenaline and thynoxine are Adenne Guanine
(c) Hormones like
oten contain non-protein amino acids.
(d) Antibietics
substances.
(e) They are precursour of many

acids$?
[MODEL QUESTION
20. What are the Significance of nucleic N
Answer:
Deoxyribonucleie acids and ribonucleic acids are the key centres which control all the c=o
metabolic àctivities of cell and in turm the whole organism. H H =
AK
(1) f there cceurs any deficiency in the DNA amount, nucleus loses its capacity to
support aderusine triphosphate (ATP) synthesis. Uracil
Cytosine Thymine
(2 Nucieus alse becomes inefficient to incorporate amino acids into proteins. Fig: Nitrogenous bases
3) Besides. DNA is the main genetic material constituting genes and chromosomes
which cary hereditary information from generation to generation. DNA helps in the
DNA contain deoxyribose sugar whereas RNA contains ribose sugar.
RNA Symthesis in the cell. if the loops of amphibian oocytic chromosome (lamp brush)
are exposed to actinomy cin (which has the property to fuse with DNA and thereby S' Carbon S' Carbon
causing decrease in DNA amount), RNA synthesis is inhibited.
M

() Recently. McConnell and Cameron (1968) have produced the evidence that RNA S

amount increases the intelligence and learning capacity of men. HOCH: HOCH

21. Define of Nucleic Acid.

[MODEL QUESTION]
Answe r:
Nucieic acids are large, organic molecules
present in living cells. DNA ard RNA are
nucleic acids. They are the polymers of
nucleotides. There are three chemically disurn
components in a nucleotide. These
E

are as follows- Phosphate group,

sugar kno
as Deoryribose or Ribose and nitrogenous 3 Carbon OH
bases. There are two types of 3 Carbon OH
bases -Purines and Pyrimidines.
Purines includes adenine
nitrogc Ribose
Deoxyribose
p'rimidines include thymine and cytosine. and guanine 2

DNA contain all 4 bases,

guanine. thymine and cytosine. But in that is, aden Fig: Structure Deoxyribose
and Ribose Sugar
RNA, thymine is replaced
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by uracil.
DNA. MODEL QUESTION]
22. Describe the
Structure of the
each
Answer: two polynucleotide chains around
helix formed by twisting of diffraction studies.
DNA is a double proposea tne DNA Structure using X-ray
Crick the helix. The
other. Watson and antiparallel to eacn Otner. ne dases are stacked inside
1

The two strands are

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24. How nucleic acids are i
POPULARPUBLICATIONS hvdrogen bonds
hydrogeN mportant
tornis tiwo Answer: for life?
hyungen bml. ldenmegukaine. All the heredilary (genetic) [MODEL QUESTION]
together via bonds with information

TI
are
e
nkoad
tosine forms thar
aihd cy
hyudnogen reproduce and mainan a new
DNA is replicated and distributed
of the cell (i.e., all the information' necessary
organism) is stored
in coded form in molecules,
to
standand DNA to daughter cells of DNA.
uble all the 'hereditary, iniormation
accumulated over
during cell division, and in
this way
from cell to cel and Irom one generation an billions of years of.evolution is
pasSed
hdngenu of organism to another.
With the aid or RNA, this information

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is expressed
synthesis. These nucleic acids are as specific patternsof
of two types: (i) deoxyribonucleic acid (DNA) proei
ribonucleic acid (RNA). DNA is the major and (11)
store of genetic information. This information
pure is transmitted by transcription into RNA molecules,
is proteins are then synthesized in a
process involving translation of the RNA.
DNAtranscription RNA translation Protein
In higher cells DNA Is localized mainly in the nucleus
as part of the chromosomes. A
small amount of DNA iS present in the cytoplasm and contained within mitochondria and
chloroplasts. RNA is found both, in the nucleus, where it is synthesized, and in the
cytoplasm, where the synthesis of proteins takes place.
AK
Nucleic acids consist of a sugar (pentose), nitrogenous bases (purines and pyrimidines),
and phosphoric acid. A nucleic acid molecule is a linear polymer in which nucleotides are
linked together by means of phosphodiester 'bridges' or bonds.
These bonds link the 3' carbon in the pentose of one nucleotide to the 5'.carbon in the
pentose of the adjacent nucleotide. Thus the backbone of a nucleic acid consists of
3 deoxyribose alternating phosphates and pentoses. The nitrogenous bases are attached to the sugarsS of
this backbon.
Fig: Hydrogen Bonding in DNA
Nucleic acids are basophilic, i.e., stain readily with basic dyes. After a mild hydrolysis
the nucleic acids are decomposed into nucleotides.
M

DNA is negatively charged due to the presence of phosphate groups. This negative [MODEL QUESTION]
charge is stabilized by basic proteins known as histone proteins. 25. Describe the structure of DNA in details.
Answer: spectrophotometrc analysis. Chemically it
. What do mean by Denaturation of DNA. It forms about. 9% part of nucleus as found by
[MODEL QUESTIONJ
consists of mainly three components: phOsphoric acid, sugar, and
bases.
Answer:
DNA exists in double stranded form. When two DNA strands 1. Phosphoric acid:
separate from each other, It, may occur also as phosphate and forms the
backbone of DNA. molecule along with
DNA is said to be denatured. Heating or alkaline
deoxyribose (pentose sugar) of two
E

pH denatures the DNA. The

temperature at which DNA double strands can be sugar molecule. It links the nucleotides by joining the
separated is known as Melting bond. These bonds connect carbon 3' in one
Temperature. Breakage of G-C base pairs needs high adjacent nucleotides with an ester-phosphate a channel for the chemical energy used by
temperature as compared to nucleotide with carbon 5' in next. This aCid
is
breakage of A-T base pairs due to triple bond in G-C
base pairs. But if denaturing agents
are removed, the DNA will regain its structure the molecule.
and it is said to be renatured.
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Boiled eggs become hard because egg

proteins and DNA gets denatured. A 2. Pentoses: and deoxyribose in DNA.
DNA has oné oxygen
example of denaturing in proteins comes classi These are of two types: ribosesin RNA sugar in nucleic acids is always ribose-, in RNA
from egg whites, which of RNA. The pentose
albumins in water. Fresh from the eggs, are typically largely eBs atom less than that OH on C-I carbon which is
egg whites are transparent it is deoxyribose. It Is always the
the thermally unstable whites turrs them and liquid. CoOK it is D-ribose and in DNA,
opaque, forming an interconnected attachnment of the base.
Quantification of DNA Content
is performed using
solid mass. the point of
Absorption at 200n
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V-uu in 2. 1ransyer or dupter RNA:
POPULAR pyrinufincs
ot ave a pen
entagona It is anotlher important type of ribonucleic
in vase sugars of 11cicc cds) acid which is present in the cytoplasi,
l-nitnogen atom
(/entose attached to pho
Mtacncd phosphoric acid there in proteinsynhesis. has been recently found that t-RNA originates trom
It
the I) are

TI
This linked todevxyribose and ribhse (i.e..Md near the nucleolar region.
nes. Both
tive
carbons, amng
which two
3. Ribosomal RNA:
th
and three ()w the base. This ribonucieic actid is the major component of cytoplasmic particles called ribosomes
Ribosomal RNA comprises up to 80% of the cellular RNA of Escherichia coli. It is ne
3. Bases:
types: site of amino acids union.
These may be of tvoa7rd (6) FPriiduns.
(a) PurineS may be ades:

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benzene rings. I hey combination
(a) Purines: the presenee of
tvo fused thymine. I he of 27. Describe the Importance of Nucleic Acids/Functions of Nucleic Acids.
nese are charsterisaiRNA
by
coMtains uracil (U)
instead of adenine [MODEL QUESTION]
(G). nucleoside. For example, IS a
(A) and gunine phasphate, forms a Answer:
penmose. minus the the corresponding nucleoside 1.e,
base plus a (adenine + ribose) IS
Deoxyribonucleic acids and ribonucleic acids are the key components which; contro
ademasine
purine base: almost all the metabolic activities in an organism
deoxy adeOsine and deoNyguanesine.
(T DNA is necessary for transferring genes from parents to ofispring.
(6) Pyrimidines: benzene ring. T hey are thymine DNA stores all the information of a cell.
the occurrence of Single
These are characterizad by
Loss of DNA content is associated with lots of diseases.
ard cytosine (C).
DNA samples are used to identify the suspect or father of an unidentified child.
AK
Nucleotides:
nucleosides, purine or pyrimidine bases
linked to as
ucleotides are phosphate esters of DNA Sequence helps in studying relationship between the two organisms such
sugars. In the nuclaxides. the 3-nitrogen of
the pyrimidine bases or the 9-N of the purine
which organism originates from vhich ancestor.
sugar, and the phosphoric acid residue is
bases is atachad to the l-carbon atom of the Without DNA, no protein synthesis will occur.
attached to the s' carbon atom oi the sugar. ..
RNA is essential for protein synthesis.
cure of genetic diseases.
RNA and DNA helps to understand the diseases and to find the
[MODEL QUESTION]
28. Describe the double helix model of DNA.
Answer: Watson and Crick (1953)
2 nm
On the basis of X-ray diffraction data of Wilkins and Franklin,
M

model for DNA structure. It is composed of two right-handed helical

proposed a
central axis. The two
polynucleotide chainse that form'a double helix around the same
5' phosphodiester links run in opposite
strands are antiparallel, meaning that their 3, perpendicular to the helical
(sce view
mnor major directions. The bases are stacked inside the helix in a plane
TOove groove
axis.
Fig: Double-helical model
of DNA bonds present between pairs of bases.
Thus nucleotides of purines are
deoxyriboadenylic acid The two strands are held.together by hydrogen sugars in the opposite strands. onlyy
E

of pyrimidines are deoxyribothymidylic and deoxyriboguanylic acid, ana Since there is a fixed distance betiween two pentose
acid and deoxyribocytidylic structure.
acid. certain base pairs can fit into the
26. What are the different bonds are formed between A and T. three are formed
As shown in figure two hydrogen
5
types of RNA?
Answer is more stable than AT pair. In addition to
[MODEL QUESTION betweenC and G, therefore a CG pair
The ribonucleic acids are established betwcen the stacked bases are-
of three types: hydrogen bonds. hydrophobic interactions
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I. Messenger RNA: double helical structure.

important in maintaining the
This ribonucleic acid is
the nucleus to the of nuclear origin and conveys
ribosomes in the genetic information
form proteins. cytoplasm, where from DNA
amino acids become groupc

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The axial of base
Sequence of bases along one
NH: ae polynucleotide
other chain the sequence
on must be complementary,chain may vary consiaeta but

TI
as given below-
-N G T
N G
s CH First chain C G T 3'
A
HC GA C
H:N Ribose
TG CAS
Guunne
Because of this property, order of bases on one
chain, the other chain is complimentary.
During duplication, the two chains dissociate

AU and each one serves as a template for the

Adenime

synthesig of 4 new complementary chain.

HN HOH.CO
N C-CH H-N 29. Describe the Structure of the RNA. [MODEL QUESTION]
Answer:
C-H RNA exists as. single stranded structure.

N
H O
C-H
o OH H
3. major classes of RNA found:
In RNA, thymine is replaced by uracil. There are

H Deoxyribose Messenger. RNA is a sequence of nucleotides that codes for proteins. In

Uracil messenger RNA, nucleotides are arranged in the form of codons.
AK
Thymane
Cytosune
and sugars Transfer RNA is used during protein synthesis. It is found in the cytoplasm.
Fig: Chemical formuláe of bases
Ribosomal RNA is also found in cytoplasm and is the most abundant RNA
found in cels.
O23 nmP
- aderine 30. Describe the Structure of RNA
[MODEL QUESTION

-® - Answer:
RNA is a long-chain molecule built up of repeating
phosphate diester bonds. Sugar component of
nucleotide units linked by 3' to S'
RNA is ribose and three out of four bases,
M

is uracil in
same as in DNA, and the fourth base
o chain,
adenine, guanine and cytosine are the
chains DNA, Uracil has one methyl group less.
place of thymine of
1.1 nm
Nucleotides: ribose, phosphoric acid and either
formed from, pentose sugar
0.29 nm RNA nucleotides are (U). Nucleotides are regarded as
phosphorylated

ani adenine guanine, cytosine or uracil.

Nucleosides are combinations of a nitrogenous base
and a
E

derivatives of nucleosides. group.

attached phosphate
pentose sugar without an

-
A single
030 nm sugar, a base and a phosphoric acid.
consists of a molecule of molecular
A nucleotide unit of nucleotide umits consisting of high
orcsne contains a large number
nucleic acid.
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029 m -s4/A. o chain

weight (about 8,000,000).
Nucleotides are the
monomeric units of the nucleic
acid macromolecule. The
a
nucleotides
heterocyclic base to the pentose.
bonding of a phosphate and
nucleoside.
result from the covalent combination of a base with the pentose forms a corresponding
108 Within the nucleotide, the adenoSine (adenine+ ribose) is the and
adenine is a purine base; adenosine diphosphate (ADP)
For example, monophosphate (AMP),
Fig Two base pairs in DNA. Complimentary bases the building
are T=A and nucleoside, and adenosine are nucleotides. Nucleotides, thus constitute
CGtinkedwith hydrogen bonds adenosine triphosphate
(ATP) transfer chemical energy.
are aiso uSed to store and
acids and they
Dlocks of nucleic
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a covalen In ribonucleic acid (RNA), the
polynucleotide chain by sunka nucleotides are
Polynuleotide: together to
form a
and 3
carbon of the
on the
the most part KNA EXISts as
a single
not arranged in double
strand. Sometimes
helical mode but
one nucleotidephosplhodiester bond, bera. olices in ome parts aue to tolding

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Nuceaides ar joined residue of and convolutions. it may form also smaler
phsphorie acid S he RN are regular acCording to These secondary helical structures
eTueen the linkage is often
ealled a 3, ana one attached
arbon and
3" carbon in RNA recent research. In
nuclevtide. This attached to the hydrogen-bonded like DNA
DNA Cent research. the formation of helix, bases
next OH groups, one exçept uracil substitutes become
to two
phosphate is esterifies sugar and pho
thymine.
nosphate
to the Scarbon. consists of alternating
polynuclevtide chain thus
backbone of a

AU
The functin
their genetic tions,juss
units. RNA is the key to
nucleotides in DNA and
The sequene of the biological activity of a particular protem.
as the sequence of
amino acids determines composed or only four dife
RNA are uually
Even though bxh DNA and nucleotides is enormous in a large
sequences of
nucleotides. the number of possible
olymer.
polynucleotide chain and have no regular helico
ical
RNA usualy exists as a single-stranded
ways, with certain
certain
configuration. Thelinear chain is thought to be folded ni lany
double-stranded regions.
ucieotides paining off and forming short
AK
31. Describe the Molecular arrangement of components in nucleic acids.
[MODEL QUESTION
Answer:
In deoxy7 cleic acid (DNA), nucleotides are arranged in the form of helixes or
chairs spirally coiling around each other. According to Watson and Crick (1962), DNA
consists of two helixes coiled about each other. The chain of each helix is made
of sugar
and phosphate group.
M

These two helixes are interconnected by the bases through

hydrogen bonds. Generally
one purine becomes attached with one pyrimidine
to form base connection between the
chain Thus, adenine along with thymine, and cytosine
connected with the sugar molecule
along with guanine becomes
of chain alternately.
*.
Sugar Thymine Adenine Sugar
Phosphate Phosphate
Sugar
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-
Adenine EE hymine Sugar
Phosphate Phosphate
Sugar-Guanine Cytosine Sugar
Phosphate
Phosphate
Sugar Cytosine
Guanine- Sugar
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fig Molecular arrangement

of components in DNA
The direction of öne helix
for the formation of is opposite to
complementary
the other. In DNA
new helix and similarly helix,i.e., adenine
cytosine effects
one helix serves as a
in one helix forms the
e nplate
the formation
of guanine in new helIX.

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S. No. ctivators ',
Enzymes

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|5 Manganese (Mn)
Peptidase, Decarboxylase
6 Molybdenum (Mo)
Glance
Chapter at a
Nitrate reductase
which are capable of
ances which
substances Nickel (N)
proteinaccous Orease
:yt* yeast) are themselves undergoing anv change.
(Gh. en= in, without Boron
Enzy nes chemical reactions of biologIeal origins

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Enolase
cataly sing
sts. orDiochemical reactin but
Enzymes are biocatalydetined enlhances tne rate Mode of Action of Enzymes
as "a protein that
An enzyme may be product." There are two viewS regrding the mode of enzyme action:
nature of final mitochondrion. The study of he
dees not atfevt the (7O*%) in the cell
are found in (1) Lock and kéy hypothesis
Maximum enzmes enzymology.
of the enzy me is known as (2) Induced fit hypothesis
cemposiuen and function
(1) Lock and key hypothesis: The hypothesis was put forward by Emit Fisher (1894). According
Classifieation of Enzymes Examples
Reaction Catalysed to this hypothesis the enzyme and its substrate have a complementary shape. The specific substrate
Group ot Enzy me molecules are bound to a specific site of the enzyme molecule.
AK
Transfer of hydrogen and| Dehydrogenases oxidases
1.Ovidoreductases (2) Induced fit hypothesis: This hypothesis was proposed by Daniel, E. Koshland (1959).
oxygen atoms or electrons According to this view, the active sites of an enzyme are not rigid. When the substrate binds to
from one substrate to another enzyme, it may induce a change in shape of the enzyme molecule in such a way that it is fit for the
2.Transferases Transfer of a specific groupIransaminase Substrate-enzyme interaction. he change in shape of the enzyme molecules can put strain on the.
(a phosphate or methyl etc.) | Kinases
substrate. This stress may help bonds to break, thus promoting the reaction.
Trom one substrate t0 another
5.Hydrolases Hydrolysis of a substrate Estrases "Lock and Key: model of substrate binding (Fischer)
Digestive enzymes
4. Isomerases Change of the molecular Phospho hexo isomerase,
M

form of the substrate Fumarase

5. Lyases Nonhydrolytic removal of a | Decarboxylases
group or addition of a group Aldolases
to a substrate
6. Ligases Joining of two molecules by Citric acid synthetase enzyme/ substrate
Synthetases) theformation of new bonds Substrie ClZyine
:complex
Inorganic part of enzyme acts as prosthetic group
in few enzyme they are
called activao
hese "Induced Fit" model ofsubstrate binding (Koshland) .
E

activators are generaly metals. Hence

these enzymes are called "Metallo enzyme suc a> Futy active *

enzyme
S. No. Activators Enzymes
conformalion

Iron (Fe)
ACOtinase, Catalase and
Cytochrome oxXIaas
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Zinc (Zn)
Dehydrogenase;
Transition ste
Carbonic andydrase Su
Copper (C) enzyme ' substrate -
Triosinase, Ascorbic,
acid oxidase substrate enzyne complex
Magnesium (Mg)
Kinase, Phosphatase

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POPULAR PUBLICATIONS Questions 9. The organelles whose majort
Choiceype Is storage of hydrolytic

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Multiple [MODEL QUESTIONI a) Centrioles enzymes are
c) Lysosomes. [MODEL QUESTION]
b) De Duve
b) Chromoplasts
"Lysosomes" were
discovered by
Purkinje. Answer: (c) d) Chloroplasts
1. d)
a) Haekel
10. A lysosome in which intracellular
c) De Vries
[MODEL QUESTIONI organells is getting digested

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Answer: (6) is called
protease a) Primary lysosome MODEL QUESTION]
is b). Acid
enzyme of lysosome Beta-galactosidase c) Autophagosome b) Secondary lysosome
2. The "marker" (muramidase)
d) Answer: (c) d) None of these
a Lysozyme
phosphatas
c) Acid
Answer:(C) lysosomes
with reference to QUESTION] short &
Long Answer Type Questions
statements is incorrect [MODEL
3. Which of the following
enzymes 1. What is Enzyme?
hydrolase and other function Answer: [MODEL QUESTION)
a) They are filled acid in structure and
monomorphic and uniform
AK
are
They may be autophagic Almost all enzymes are proteins. There are some nucleic acids
C)They and polysaccharides These are called ribozymes. One can depict an enzyme by a
that behave like enzymes.
proteins, nuclei acids, lipids line diagram. An enzyme
d) They can digest like any protein has a primary structure, i.e., amino acid sequence
Answer: (b) of the protein. An
enzyme like any protein has the secondary and the tertiary
[MODEL QUESTION structure. In the tertiary
has single membrane structure it will be noticed that the backbone of the protein chain folds upon itself,
4. Which of the following organ b) Cell wall
the
a) NucleuUs
chain criss-crosses itself and hence, many crevices or pockets are made. One such pocket
c) Mitochondria d) Spherosomes is the 'active site'. An active site of an enzyme is a crevice or pocket into which the
Answer: (6) substrate fits. Thus enzymes, through their active site, catalyse reactions at
a high rate.
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[MODEL QUESTION] 2. How enzyme is different from inorganic catalysts?

5. Lysosomes are rich in [MODEL QUESTIQN
a) Polyribosome b)Lipoproteins Answer:
c) DNA ligase d)Hydrolytic enzymes Enzyme catalysts differ from inorganic catalysts in many ways, but one major difference
Answer: (b) needs mention. Inorganic catalysts work efticientlye at high temperatures and high
pressures, while enzymes get damaged at high temperatures (say above 40°C). However,
6. Lysosomes are generally found in [MODEL QUESTION]
enzymes isolated from organisms who normally live under extremely high temperatures
a) Animal cells onlyY b) Animal cell and in some plant cells
(e.g., hot vents and sulphur springs), are stable and retain their catalytic power even at
c) Plant cells only d) Bacterial cells
E

high temperatures. (upto 80°-90°C).

Answer: (b)
3.Whatare the Biological Importance of Enzyme? [MODEL QUESTION]
7. Which of the function is performed by lysosome [MODEL QUESTION]
a) Breakdown of cell substances b) Photosynthesis
Answer:
c) Breakdown of water Th sar of chemical reactions are taking place in the body of a living organism, all,
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d) Synthesis of protein
Answer: (a) of them are mediated by enzymes.
operate at biological temperatures.
) Enzymes are specialized catalysts that
do not require harsh treatment.
8. At which pH enzymes of Lysosomes,are
usually active [MODEL QUESTION l1) enzyme mediated reactions operate in different parts
a) pH 5 b) pH7 C) pH 8 (V) They are pH specific so that reactions requiring ditferent pH
Answer: (a) d) In any pH of the body.
conditions, enzymes force the organisms to live
(V As they operate under favourable
under favourable environment
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POPULAR PUBLICATIONS controllea by Answer:
fomnation is
De fnction In older imes enzyines were
regulated. Their C1zneso or classified into

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certan (i) Hydrolyzing:
nzynesandarerepression
highly
of
genes allo
Catalyzing nyarolysis ot
two broad categories.
Cvation amylases,prolcases, Iipases,
large molecules
into smaller ones,
nontunctional in cells. [MODEL QUESTION] esterases, phosphorylases, e.g., tarbohydratess or
Nature Of Enzymes?
hydrolyzing In nalurc. I hey amidascs. Diagestive enzymes are
are often grouped
4. Describe the Chenmical exCcption of resn. and lipolytic intothree types- proteolytic, amyioyuc
(Sumner, 1926) With
the cently
Answer: a nonpro. (ii) Desmolysing:
enzymes are globular proteins enzymesmay adanoky conain

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rotein Catalyzing reactions other than
enzymes. Some and coijugate. hyroysis, e.g., aldolases,
discovered RNa types of enzymes. simple peroxidases, catalase, carboxylases, dehydrogenases, oxidases,
made up or protein. Active.sité
group. Acvordingly there are two etc.
enzyme which is wholly The modern system of enzyme classification
Simple Enzyme lt is an amino acids. Additional
substance or grom
oup i Biochemistry (IUB) in 1961. It groups was introduced by interational Union
specitic grvuping ot its own enzymes into the following six categories
of
Tormed by
urease. (a) Oxidoreductuses
absent. e.g. pepsin. trypsin, parts- a protein pat
which is formed of tow
Conjugate Enzyme. lt is an enzyme . The They take par in oxidation and reduction reactions
and a. nonprotein part named cofac or transfer of electrons.
called apoenzyme (e.g. tlavoprotein) Oxidoreductäses are of three types- oxidases,
complete conjugateenzy me. consisting of
an, apoenzyme and a cofactor, is reductases, e.g
dehydrogenases and

called holoenzyme. Active site is fornmed jointly bapoenzyme

and cofactor.
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Cycytochrome oxidase (oxidizes.cytochrome), succinate dehydrogenase,
nitrate reductase.
5. What do you understand by Active Site or Active Spot? [MODEL QUESTION (b) Truusferuses
Answer: They transjer a group from one molecule to another e,g, glutamate-pyruvate
The whole of enzyme molecule is not active in catalyzing a chemical reaction. Only a
transaminase (transfers amino group from glutamate to pyruvate durinig synthesis of
small portion of it is active. It is called active site or active spot. alanine). The chemical group transfer does not occur in free state.
Subsrate (c) Hydrolases
They catalysehydrolysisof bonds like ester, ether, peptide, glycosidic, C- C, C-- halide, P
- N, ctc. which are formed by dehydration condensation. Hydrolases break up large
M

Enzyme-substrate molecules into smaller ones with the help of hydrogen and hydroxyl groups of water
complex
molecules. The phenomenon is called hydrolysis. Digestive enzymes, belong to this
group, e.g., amylase (hydrolysis of starch), sucrose, lactase.
Active (d) Lyases
Site The enymes cause cleavage, removal ot groupS without hydrolysis, addition of groups to
double bonds or removal of a group producing double, e.g, histidine decarboxylase
(breaks histidine to glyceraldehydes phosphate).
(e) Isomerases
E

Ihe enzymes cause rearrangement Or molecular

structure to effect isomeric changes.
to ketose group or vice- versa like glucose 6-
They are of three types, isomerases (aldose
Enzyme poSition of one constituent or
phosphate to fructose 6-phosphate). epimerases (change in and mutases ( shifting the
An enzyme may have one to
several active sites. carbon group like xylulose phosphate to ribulose phosphate)phosphate).
to glucose-1-
An active site or spot is an area position of side group like glucose-b-phosphate
AR

holding particularsubstrate of the enzyme which and

is capable of attract
molecules by its specific as Ligases (synthetases)bonding of two chemicals with the help of energy obtained from
to allow the chemical change.
It fails to recognize charge, size and shap
SO
The enzymes catalyse as -0, C- S, C-N and P- 0, e,g., pyruvate
other molecules. ATP resulting in formation.of such bonds
6/What are the different classes It combines pyruvjc acid with CO to produce Oxaloacetic acid. .

of Enzymes? carboxylase.
[MODEL QUESTION
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POPULAR PUBLIÇATION
Enzynmes. BIOLOGY
(Properties) of temperature. Enzyme
becom

TI
Characteristics yond maximum temperature. inactive
escribe the :ave additi below minimum
Answer: are: globular
protems. They iay
itional
Otinum pll: lvery enzyme has an optimum temperatur and
Properties of Enzymes
Enzymes are
generall pll reduces enzyme acuvity pH when it is most
moiccules wil by changing effective.
nature: A
ten
aie or organie
substances for their
weight: Being
actu
pateinaavus, the enzi meS
are gant
+,o00,0OU (PVruvale
dehydrogen
A change in pt may aiso start
(3) Enzyme concentration:
reverse reaction.
the degree of ionization
of its side chains.
*olecular odAW (hucteria!
ternadonin) to onZyme concentration
The rate
of a biochemical reaction

AU
upto a pont called rises with the increase in
toiecular weight ot state. limiting or saturation
hydnisol in the tree 4) Product concentration: point.
complen). úryphilie and form increase the rate f lt the products
are
nature: They are hy reaction but Revers reaction can also start. allowed to remain in
the area oI the
.Colloidal Enzymes de not start
a chemical ver
adOUt equilibrium ery
.Chemical Reaction: equilibrium but bring (5) Activators: Ihey increase activity
change the of enzymes
Chemieal reaction. They do na function as cofactors (e.g, K , (e.g.. chloride for salivary amylase),
Mn*) and convert proenzymes
sovn. per minute by a molecule or (6) Protein poisons: Cyanides, azides, to enzyme state.
sudstrate molacules changed iodoacetate, and salts
5) Efmciency: The number of turn-over number, the more tertiary.structure ot enzymes by either combining of heavy metals destroy
number (4**): The higher thne
enzyme is called turn over with cofactor or a group of apoenzyme
an enzyme
(-SH group, -COOH).
etficient i or usea up in the chemical (7) Radiation Energy: High energy radiations
in no way transtormea
6) Unchanged Fornm: Enzymes are break hydrogen bonds, ionic bonds, and
AK
reaction. other weak linkages to destroy enzyme structure.
reacton dut come cut unchangad at the end of
) Reversibility: Theoretically, all enzyme
controlled reactions are reversible. (8) Substrate Concentration: Increase in substrate
concentration increases the rate of
Reversibility is. howerer. daperdent upon energy requiremens, availability of reactants, reaction. The enhanced rate is due to two factors:
cencentration of end prducts and pH. (a) occupation of more and more active sites by
the substrate molecules;
8) Enzyme specificity: Enzymes are highly specific in their action. For example, enzyme (b) higher number of collisions between subctrate molecules.
The rise in velocity.
maltase acts on sugar maltose but not on lactose or sucrose. Different enzymes may act is quite high in the beginning but it decreases
progressively with the increase in
on the same suhstrare bur give rise to ditferent products. For example, raftinose gives rise substrate concentration.
tomelitiose and tructose in the presence of enzyme an enzyme may act on different Michaelis Constant
Substrates. eg. sucrose can act on both sucrose and raftinose producing (MichaelisMenten Constant, Km). it is a mathematical derivation or constant which
different end
M

products. indicates the chemical reaction catalysed by an enzyme attains half 1ts maximum
9) Heat Sensitivity: All enzymes are heat velocity.
sensitive or thermolabile. Most enzymes
operafe optimally between 25' 35°C.
-

10) Protein poisons: Being made 9. What do.you

of proteins, enzymes are inactivated or denatured mean by Activation Energy? [MODEL QUESTION]
those substances and forces which destroy by all
energy radiations. A nswer:
12) pH: Each enzyme functions
at a particular pH. e.g., pepsin Most of the chemical reactions do not start automatically because the reactant nmolecules
salivar amy lase (6.8pH). trypsin (2pH), sucrose (4.5 pH).
inetfective.
(8.5pH). a change in
pH makes the enzymed have an energy barrier to become reactive. The energy barrier may be on account of
A Mutuarepulsion due to presence of electrons over their surfaces.
E

13) Enzyme- substrate

Complex: The active sites B Salvation or holding of reactants in solution form by hydrogen bonds.
conformation for atiracting of enzymes have a specinc
and holding substrate. It
where the substrate fíts in
a complementary fashion.
usually possess a crevice or
poCK
C) Reaction sites of the reactive molecules beinig smalil, precise collisions do not occur.
supply of energy is needed for the start of the chemical reaction. It
herefore, an externalenergy.
8. Mention the Is called activation Activation energy of the system and brings about forceful
factog which are influencing
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the enzyme collisionis between the reactants. The requirements of activation energy is quite high.
activities?
Answer: [MODEL QUESTION]
Factors Influencing Enzyme V10. Explain the Mode Of Enzyme Action. [MODEL QUESTION]
(1) Temperature: Activity Answer:
An enzyes
temperature at generally active within a narrow here are two view points by which enzymes are supposed to bring about chemical
coTesponds to range
animals.e.g., 37°C
in human beingsEnzyme the body temperatureof temperatur. The reaction.
activity decreases of warm bIo cd (1) Lockand key hypothesis. It was put 1orvard by Emil Fischer in 1894. According to
above and below this hypothesis, both enzyme and substrate molecules have specific geomtrical shapes.
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ne Chyne iS such
contguraioN ol stlCs also contailloluw forlis of an cnZyme occurring in.the some
surtidce
it. The ictive
in special ivity are callcdiisoezymes or isozymes. organism and having

TI
sites the a similar substrae
n te rgion of actie molerules tu be hehl o1er comict with the together causing
substrate estiblishing the
tne paticular -SH tor What are the inhibitoes of Enzyme
NH', CORI, 2.

--
SFoups having - Action?
Answer: [MODEL QUESTION]
chemixal chngo.
Inbibition of Enzyme Action
Deduction or stoppage ol enzyme
Lock and key model activity due to presence

AU micals is, called enzyme inhibition. It is of several

chem of adverse conditions or
types. Inhibition can be classilicd
into two
(a) Competitive and noncompetitive
(b) Reversible and irreversible
Competitive inhibition is caused by swamping
of the active sites by a chemical which is
similar in structure to the substrate but does not
undergo chemical change. Competitive
inhibition is usually reversible. Non competitive inhibition is caused by
-

alteration of
conformation of the enzyme by a chemical that binds to a site other than the active site.
some time so Ihat an enzyme-produes Irreversible inhibition is of permanent nature as the enzyme conformation is harned.
AK
The pradcts remain attached to the anzyme for
complex is also formed. However, the products are sOon releasea and the freed enzyme is
Denaturation ot enzyme is an example of irreversible inhibition. Reversible inhihition is
able to bind more substrate malecules. thatinhibiuon which can be overcome by withdrawal of the inhibitor because the effect
Enzyme -Substrate- Enzyme Substrate ConipleX of the latter is of temporary nature due tó blocking of active site or binding to linkages
required for maintenance of active site. Dilution and dialysis reduces or climinates the
Enzyme-Substrate Complex ~-- enzyme-products. complex
effect of reversible inhibition.
Enzyme -Products Complex-Enzyme+ Products
(2) Induced-fit theory. It is modification of lock and key hypothesis (1) Protein Denaturation. Enzyme activity is, dependent upon the maintenance of
by Koshlarnd in 1959. According to this
which was proposed tertiary structure of the protein moiety.the latter is destroyed by several factors like heat,
theory the active site of the enzyime contains two
groups, butressing and catalytic. The buttressing group is meant
for. supporting the
high energy radiatons and salts of heavy metals.
substrate. The catalytic groups are normally at a distance. 2) Competitive Inhibition. It is the inhibition of enzyme activity by the presence of a
M

As soon as the substrate comes

---
in contact with the buttressing group,
the active site of the enzyme undergoes chemical that competes with the substrate for binding to the active site of the enzyme.
contomational changes so as to bring the catalytic group chemical is, also called substrate analogue or competitive inhibitor. It
The inhibitor substrate
opposite the substrate bonds to
be broken. resembles the in/tructure and gets bound up to the active site of the enzyme
without getting transformed by the latter.
Induced fit hypothesis 8) Non- competitive Inhibition. It is.an irreversible inhibition of enzyme activity by the
presence of a substance that has no structural similarity with the substrate. It is of two
types, reversible and irreversible. The irreversible noncoinpetitive inhibitor destroys or
combines irreversibility with a functional group of enzyme that is essential for its
E

catalytic function. inhibition

(4) Allosteric Modulation or Feed Back Inhibition. lt is a type of reversible
O Tound in allosteric enzymes. The inhibitor is noncompetitive
and is usually a low
a chain of reactions
molecular jntermediate or product of a metabolie pathway having
end product or feedback
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involving a number of enzymes. It is, theretore, also called

11. What is Isoenzymes Inhibition. The inhibitor is also called modulator.
(Isozymes)?
Answer
At one time it was [MODEL QUESTION
believed
a metabolic reaction. It that an organism has only a single
was later discovered enzyme for a of
number of variants that a substrate given
of an enzyme producing the may be acted upo y aa
same product. BIO-99
The multiple mo
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INFORMATION watson and cricks suggestion of the
oi the parent strand as template was complementary strand synthesis
one of taking

TI
proposed in
[MODEL QUESTIONJ
a) 1869 b) 1909
Chapter at a Glance
c) 1953
) 1952
Answer: (c)
nulei in 1S70
frvm
DAA was fist extrastd 4. Which of the following statements is true with respect to the

AU
their SUNe. phosphorous. DNA double helix?
named nuclem sisatr- detemured that DNA was a weak acid rich in [MODEL QUESTION]
Chemical analy deoxyribose nucleic acid: -it contains
co
intermativn about DNA: -
a a) Composed of two or more polynucleotide chains
lts name prov ides a lot ef and is found in the nucleus.
(darnyridse), - it is weakly acidic.- b) The base pairs have opposite polarity
sugar nwiety
nurlear lxalzation - subsequent
Identification a
as compinönent of c) Covalent bond exists in base pairing
Because of its: -

3 Are genes composed

as a carrier of genetic intorimation. d) T is transcribed as U
chremosomes it was irnpliated
-

ot DXA er prvtein Answer:(b)

to contain protein so early on it was a challenge
Chroresvnes are also Anon
information Who, in which year showed firm enzymological proof that DNA alone functions
demonstrate that DNA was indeed the molecule that contained the genetic .

5.
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DNA Onily four ditterent subunits make up DNA- Chromosomes contain less DNA than [MODEL QUESTION]
as the template for the synthesis of new DNA strands?
protein by weight Watson and Crick in 1953
a)
Preten Z0 different subunits greater potential variety of combinations - Chromosomes Avery, MacCarty and Macleod in 1944
b)
contain more preiein than DNA by weight ana Stahl in 1958
c) Meselson
Classical experimental data confirmed DNA as the genetic materiai.
d) Hershey'and Chase in 1952
Answer: (C)
Multiple Choice Type Questions
[MODEL QUESTION]
6. Replication of DNA ends are carried out by polymerase.
Both ) none
1. Who were the first to suggest that one strand of DNA might a) True b) False
M

the synthesis of its complementary

act as a template for **

strand?. [MODEL QUESTION Answer: (b).

a) Meselson and Stahl
c) Walter Flemming b) Watson and crick basic mechanism of gene expression is
d) Rosalind Franklin and
Maurice Wilkins T. Which of the following regarding the [MODEL QUESTION]
Answer: (b)
correct?.
a) DNA>tRNA-> protein protein
b) RNA ->¢DNA-> mRNA->
2.Semiconservative nature of
replication of eukaryotic
demonstrated by chromosome was ) RNA-> DNA-
mRNA -> protein
E

a) Walter Flemming on root

tip cells of Viciafaba MODEL QUESTIONJ d) DNA-> protein
b) J. Herbert Taylor,
Philip Wood and Answer: (6)
Viciafaba Walter Hughes on root tip ce
c) Walter Flemming on root tip not take part in gene expression?
d) J. Herbert Taylor, cells of Phaseolus 8. Which of the following does [MODEL QUESTION]
Philip Wood vulgaris
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and Walter. Hughes on b) Transcription

of
Phaseolus vulgaris cells
Answer: (b) root P a) Replication d) Translation
c) RNA processin9
Answer: (a)
be formed at the
same time.
could
Multiple copies of RNA [MODEL QUESTION
c) Both d) none
b) False
a) True
Answer: (a)
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polypoptido must bo atta.
tacho
incorporation into MODEL OT UESTIO to Rough strain Sooth stram

TI
prior to their proved this and when? (11-R) Ileat-killed
T0. Amino acids Who (II1-S) Rough-killed & Heat
molecule. sniooth strain
special adaptor killed sooth stran
in 1955 in 1957
a) Francis H. Crick B. Hoagland
and Maholon
Paul C. 2amecnic in 1953
0 Francis H. Crick
C) James Watson and
d) Linus Pauling in 1950
Answer: h

1. What is the
Answer:
Short &Long Answer Type
Structure of the DNA?
Cuesttions
(MODEL QUESTION

The doutie belical structur of DNA was cracked by Watson-and Crick based on the
ay orystaiography results. DNA is a double helical structure. Each strand DNA
ofa
AU
AK
elin is comprsai of ngeating units of nucleotides. Nucleotide consists of
compenerts: bse or denribose sugar, nitrogenous base (purins or pyrimidines) and
phasphate. Mouse lives Mouse dies Mouse lives Nfouse dies
DNA is reaiveiy charged due to the presence of negatively
charged phosphate groups.
This negatively charged phosphate groups
are stabilized by basic proteins known as 3. What is Central Dogma of Molecular Biology? [MODEL QUESTION]
histone.
Answer:
It is an explanation about how the flow of genetic information occurs in à biological
2. Explain how DNA acts
as a Genetic Material.
[MODEL QUESTION] system. This explains how DNA replicates and then gets converted into messenger RNA
M

Answer:
(mRNA) via transcription: Then this mRNA is translated to fom proteins.,
Grntith perormad an experiment
known as transforming experiment.
of Preumococeus These He used two strains
strains used were
wo different strains were used
ype l-S (smooth), to infect the mice. The two
polysaccharide and that contains outer capsule Proteins
the bacteria from
type II-R (rough) strain
do not contain capsule. made up o ONATranscripbon RNA ransiabon
the host immune system. The capsule protecis
The Griith experiment
E

is explained below- Central dogma of molecular biology

Rough strain of Pneumococcus
Smooth strain isinjected in mouse.
of Pneumococcus is The mouse is alive 4. What is DNA Replication? [MODEL QUESTION]
When heat killed injected in mouse:
smooth strain
mouse is alive. of Pneumococcus The mouse dies. Answer:
from a single
is a process of producing two identical copies of DNA
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is injected into mouse, the DNA Replication

In tbe last set
into mouse. The
of experiment, rough
strain ánd heat DNA molecule. It is a process of biological inheritance. DNA is a double helix in which
mouse dies. killed smooth strain wo strands are complementary to each other. hese tivo strands of a helix separate at the
I

This proves that is inj cted

there is some transforming molecules. Out of the two strands of DNA
is converting
or transforming substance ime of replication to form two new DNA and
the death of the mouse. the rough present in heat
killed S Tormed, one is identical to one of the strand another strand is conmplementary to the
This transformingstrain into virulent strain stralnt as replication. Before
Later on. Avery.
McLeod McCaty substance is that is responsio or parent strand. This form of replication is Known semi-conservative
in S phase of interphase.
genetic material. and Hershey DNA. ne cell enters the mitosis. the DNA is replicatedenzyme
and Chase involved in DNA replication.
confirms that DNAis a DNA polymerase in the most important

BIO-102 BIO-103
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(believed to occur normal|
ormally in most cells),
POPULAR PUBLICATIQNS [MODEL QUESTIONI conditic three special transfers
only under specific conditions
der speciic in case of some (known o

TI
transfers (believed viruses or in a laboratory), and thrce
n never to occur)
Transcription?
5. What is
messenger RNA from
DNA belore 2neral transfers describe the normal
The gern flow of biological information:
Answer: formation of RNA
sueh as
one of tlhe strand S)e copied to DNA (DNA replication), DNA information
DNA canbe
t 1sa praess of oceurs. During transeriptio1, DNA can be copied
CNpresston or protein
synthesis .of nRNA
mRNA occurs via RNA mRNA (transcription), and proteins can
fornmation. The synthesis be synthesized using the information in
acts as template tor
mRNA
for a particular DNA
segment which RNA as a template (\ranslation). The special transfers describe: RNA

AU
Transeription usually occurs ,being copied
from RNA (RNA replication), DNA-being synthesised
polymerase enzy me.
enpression. Other than the mesScnger KNA, other f using an RNA templae (reverse
required further for gene transer: transcription), ana
RNA. mieno RNA. small
nuclear RNA can also be ribed ir proteins Delng synthesised directly from a DNA template without the
KNA such as ribosomal se of mRNA. The unknown transfers describe: a protein being copied from a protein,
use
the similar manner. synthesis of RNA using the primary structure of a protein as a template, and DNA
reverse transceription. Tney are abie to convert RNA
RA
Some viruses have a property of syrithesis uSing the primary structure of a protein as a templaté these are not thought to
is known as reverse transcriptase.
-

template into DNA. The enzyme used

causes "AIDS. naturally occur.
For Example: Human immunodeticiency virus that

[MODEL QUESTION General Special Unknown

AK
6. What is Translation?
Answer: DNA DNA RNA DNA Protein DNA

This is the provess of gene expression or protein synthesis that occurs in cytosol. DNA-RNA. RNARNA ProteiriRNA
RNA Protein DNA -Protein |
Protein>Protein ::
Ribsomes are the celi organelles that are involved in protein synthesis. The messenger
.

RNA formed by the process of transcription is decoded by

ribosomes to förm á [MODEL QUESTION]
polypeptide made up of amino acids. Messenger. RNA is What is DNA fingerprints?
9.
composed of polymer of
nucleotides or codon. Each codon consists of 3 nucleotides
that will code for.a single Answer: the differences in
locating
amino acid. There are some important components DNA fingerprinting is a method of identifying the DNA by
that are involved in protein synthesis specifiç: regios of the DNA sequence which
ibosomes. messenger RNA and transfer RNA (IRNA). the arrangement of nucleotides in those DNA profiling..
are repeated several times. The technique is calld DNA typing or
M

Transfer RNA is involved in physically .

linking mRNA and the amino differences. in. the 'repetitive DNA
proteins. acid sequence of ,DNA fingerprinting involyes identifying
Sequences. DNA
7. What is Biological
sequence information? The repetitive DNA is called satellite identity of viçtims from.
Answer: [MODEL QUESTION Variation satellite DNA is very useful in establishing the
The biopolymers
in roots, tears or saliva and in solving paternitý disputes.
each moromer is
that comprise DNA, RNA and
(poly).peptides are lineär blood stains, semen stains, hair
connected to at most two polymers (1.
monomers effectively other monomers).
E

encodes information. The The sequence or Applications of DNA fingerprinting:

cemral dogma ideally transfers of information criminals or potential suspcts and relieving people
sequence is, used
are faithful, deterministic described Dy lt helps in identification of
as a template for transfers, wherein
sequence that is entirely the construction one biopoiy wrongly accused of crimes. members of the same family.
dependent on the ornginal of, another biopolymer w blood relationships in the
lt is used to infer
biopolymer's sequence. real parents of a given offspring.
t is used to determine to the
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8. How differenttypes actual parents in case of a lost child.

of sequential information is used to determine the victims or of.
Answer: transfers? It sex ot badly damaged bodies of accident
The MODEL QUES lt is used to determine the
dogma
of sequene intormation a framework
for archaeological specimens.
between information-carrying understanding transfer
or general case. in the
iiving organisms. biopolymers,
There are 3 major classes in the most C mmon
and protein. There are of Such biopolymers: DNA
5*3= conceivable and RNA (both
nucleic aacids). BIO-105
between these. The
dogma classes these direct transfers of information
into 3 groups that can ccur
of 3: three general tra sfers
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3.
a-helical model of protein was discovered

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a) Pauling and Correy
by [MODELQUESTION]
b) Watson
c) Morgan
d) BerzeluS
Answer: (a)

at a Glance 4. Aleurone
grains are
Chapter [MODEL QUESTION]
a) Enzymes

AU
b) Carbohydrates
usea by G. J. Mulder f. c) Protein ) Fat
Proteins by Berzelius in 1838 and Was Answer: (c)
The word prvein was coinai
IS40. 16% nitrogen sn
protein. Average proteins contain
of protoplasm is made up of 5. High content of lysine is present in
( o and sulphur 0.3- 0.370. Iron. phosphorous. us. copper, [MODEL QUESTION]
carbon. oy gen 20-24°s. hydngen a) Wheat b) Apple c) Maize d) Banana
calcium, and iodine are also present in small quantiuy. Answer: (a)
) Sructure of proteins: It is due to ditferent
rearrangement of ino
anmino acids. When
When carboxyl
c

or another amino acid the bond?.

group of one aminw acid kindad with amino group (- NH:)
calied peptide bond. A Feptide may be dipeptide. tripeptide and polypeptide. The simplest rotein 6. Which of the following is polymerized to form proteins [MODEL QUESTIONI
a) Protein
AK
is Insulin. Acconding to Sanger ( 1953) insulin consists of 51 amino acids. A protein can have up
up b) Carbohydrates
to c) Amino acid
four level of centoamation. d) Muramic acid
Primary structure: The primary structure is the covalent connections of a protein. It refers to Answer: (C)
linear sequence. number and nature of amino acids bonded together witn peptide
bonds only. e.g.
ribonuclease. insuiin. haemoglobin. etc. 7. Basic structure of protein was given by [MODEL QUESTION]
(i) Secondary structure: The folding of a linear a) Stanley b) Nicholson
polypeptide chain into specitic coiled structure c) Watson d) Singer
(a- helix) is calied
seondar structure and if it is with intermólecular hydrogen bonds
structure is known as B- pleated sheet. - helical the Answer: (a)
a structure is found in protein df fur,
hair claus. and feathers. 5 pleated
structure is found in silk fibres.
keratin of
(un) Tertiary structure: 8. Weightof protein is. [MODEL QUESTION]
The arrangement and interconnection
of proteins into specific loops and a) 12000 b) 6000 C)12000 d) 600 3000
M

bends is called tertian

structure of proteins. It is stabilized
hydraphobic bond and
disulphide bonds. It is found by hydrogen bond,
ionic bond, Answer: (a)
in myoglobin
(v) Quaternar structure:
it is shown by protein (globular proteins).
protein consists of identical containing more than
units. It is known as one peptide chain. The 9. Which of the following is the simplest amino acid [MODEL QUESTION]
deiydregenase. If homologous quaternary b) Asparagine
the units are dissimilar, it is structure e.g. lacue a) Tyrosine
hemaglobin which called as heterogeneous
censists oftwo a - chains quaternary structure s c) Glycine d) Alanine
and two'-chains.
Answer: (¢) "

Multiple Choice Type

Questions Short&Long Answer Type guestions
E

1.Proteins consist
of
a) carbon, hydrogen,
b) Carbon, hydrogen, chlorine, sulphur [MODEL QUESTION] 1. What is Protein? [MODEL QUESTION]
c) Carbon, manganese, oxygen, nitrogen Answer:
he word. protein was coinèd by, Berzelius in 1838 and, was used by G. Mulder first
d) Carbon, phosphorus, nitrogen J.
iodine, oxygen
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Answer: (b) and inorganicC time 1840.

phosphate
15% of protoplasm is made up of protein.
2. Which
of the following Average proteins contain 16% nitrogen, sU-53% carbon, oxygen 20-24%, hydrogen 7%
a) chromoproteins is conjugated and sulphur 0.3 0.5%. Iron, phosphorous, copper, calcium, and iodine are also present
c) Glycoprotein protein
EMODEL QUESTION)
b) Phosphoproteinn in small quantity.
Answer: (d)
d) All of
the abovee [MODEL QUSTIQN
Describe the Structure of Proteins.
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cardONYT group (-COOll) shape
Answer: amo acids. \ ncn On the basis of
different rearrangement of ibroIs

TI
ot anoner anmino acid
acid the protein/Scleroprotein: Insoluble
t Is due to gnup (- NIE) bond in water.
one anin acid bondad with
anino
Iripepide änd polypen
eptide is teolytic
proteo enzyme is spirally coiled Animal protein resistant
be dipeptide, thread like structure
called peptide boni. peptide mty
Acconting to Sanger (1993)
Insulin onsists
consists of sThe
ot Sl amino annective tissue), actun and myoSin,
conne form fibres. e.g. collagen (n
keratin in hairs, claws, feathers,
SInplest protein is Insulin. Gi Globular protemIS: Soluble in water. Polypeptides etc.
four level of contormation. coiled about themselves to f
aCids. A prvtein can have up te
structure is the covalent
connections of a oval or spherical molecules e.g albumin insulin
hormones like ACTH, oxytosin, etc.
(Primury structure: The primaryand nature of amino acids bonded together withn

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peptide
eters to linear sequerne, number haemoglobiR, erc. On the basis of constituents
bonds only. eg. ribonuclease, insulin, ) Simple proteims:The proteins which are made up of amino acids only. e.g. albumins,
globulins, prolamins, glutelins, histones, etc.
HN Anma acn Peptide bond
(i) Conjugated proleins: 'These are complex proteins çombined with characterstic non-F
amino acid substance called as prosthetic group. These are of following types:
COO (a) Nucleoproteins: Combination of protein and nucleic acids, found in
chromosomes and ribosomes. e.g.'deoxyribonucleoproteins, ribonucleoproteins,
etc.
PRILARY STRUCTURE
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(b) Mucoproteins: These are combined with large amount (more than 4%) of
carbohydrates e.g. mucin.
(i) Secondary. structure: The folding of a linear polypeptide chain
into specific coiled (c) Glycoproteins: In this, carbohydrate content is less (about 2 3%) e.g.
structure (u helix) is called sæcondary structure and it S with intermolecular hydrogen
if immunoglobulins or antibiotics.
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bonds the structure is known as B-pleated sheet. a -helical structure, are compounds of protein and coloured pigments. e.g
is found in protein of (d) Chromoproteins: These
fur. keratin of hair claws, and feathers. 8-pleated structure is
found in
silk fibres. haemoglobin, cytochrome, etc.
e.g. cholesterol
SECONDARY STRUCTURE (e) Lipoproteins: These are water soluble proteins and contain lipids.
Alpha-Helix and serum lipoproteins.
Beta-Sheet (1) Metaloprotein: These are metal binding proteins,
AB-globin known as
copper e,g. chlorophyll.
transferring is capable of combining with iron, zinc and
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phosphate e.g. casein (milk) and

(g) Phosphoprotein: They composed of protein and
vitellin (eg8)
are hydrolysed by acids, alkalies or enzymes, the
(ii) Derived proteins: When proleins
them are called derived proteins. On the basis of
(iii) Tertiary structure: degredation products obtained from proteoses, secondary
are classified as primary
loops and bends is called
The arangement and interconnection progressive cleavage, derived proteins
tertiary structure of proteins. of proteins into sp proteoses, peptones, polypeptides, amino
acids, etc.
ionic bond, hydrophobic It is stabilized by hydrogen
bond and disulphide bo
bonds. It is found in myoglobin
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proteins). (glo0 On the basis of nature of molecules acids.. e.g. blood

(v) Quaternary structure: It as anion and include acidic amino
The protein consists
is shown by
protein containing more () Acidic proteins: They exist
of identical units. It is known
e.g. lactic dehydrogenase. than one peptru re groups. e.g. lysine,
as homologous quaternary as cations and rich in basic amino acids
quaternary structure If the units are s (i) Basic proteins: They exist
e.g. hemoglobin which dissimilar, it is called as hetero eneous arginineetc.
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consists of two [MODEL QUESTIONJ

3. What are the a -chains and two D hains. by hierarchy of Proteins?
different classes of What do you understand
4.
Answer: Proteins?
[MODEL QUESTIONJ Answer: that:
Classification of Proteins this hierarchy are characteristic, interactions and
Proteins are classified on he, implications of
level of is neld together by
the hierarchy
the basis of their
shape, constitution
each
and function. fortes
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in the hierareny 5. BIOLOGY
higher levels of structure levels
of Prote
elements) of the lower Answer:
(also called that this four-level
hierarchy. of protein structure [MODEL
(i) Proteins occur.as food reserves

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QUESTION]
towever, subsequent work has revealeddimensional structure of. proteins can can now as glutelin, globulin
1Sa bit too simple and the three be (i) Proteins are coagulated in solutions,
hierarchy, which includes: milk.
Conveniently deseribed by a six level structural such as.Zn, Ca, Hg°" etc. Casein alkaline to
the isoelectric pH by
pH 4.6, cyt. positive ions
lysozyme l1.0 etc.
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primary structure C-9.8,resum globulin 5.4,

Gi) Proteins are the most pepsin 2./,
secondary structure diverse molecule
(iv) Proteins work as on the earth.

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supersecondary structure horinone as insulin
domain structure () Antibiotics as gramicidin, tyrocidin and glucagon.
and penicillin are
tertiary structure (vi) They are structural component peptides.
of cell.
quaternary structure. (vii) They are biological buffers.
(viii) Monellin is the sweetest substance
Quaierrar obtained from African
Two or more polypeptides ASsoCiations of than sucrose). berry (2000 time sweeter
STucture each polypeptide a subunir tertiary struclure (ix) Proteins helps in defence, movement
activity of muscles, visual pigments receptor
More compact strcures molecules, etc.
(x) Natural silk is a polyamide and artificial silk is
a polysaccharide. Nitrogen is the basic
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Tertiary Multidomain (mosaic) Associations of constituent."
Structure or single domain domain structure
6. What do you understand by Motif? [MODEL QUESTION]
Dorain Structure
folds or Madules
All alpha, all beta, Units of tertiary Answer:.
alp.a+p structure A motif can be either a structural or a sequence motif:
A structural motif is the arrangement of atoms in 3-D space to produce a
Super secondary Associates of
a-a. P-a-p, greek key particular structural pattern eg. alpha helix, beta sheet.
STuctire Secondary.
helix-loop-helix
structure A sequence motif is a particular pattern in the sequence of amino.acids or
Secordary nucleotides.
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Structure a-helix P-sheet -tums loop Units of

secondary A structural or sequence motif may or may not have a particular function associated with
Primary Structure it.
-P-R-K-F-F-V-G-G-N-W-K-M-N-G-D-K-K-
Struciure
:LinearaminoSequence
of 7.Describe the structure ad functions of primary Proteins. [MODEL QUESTION]
acids
The definitions of Answer:
primary, secondary, tertiary, structure which refers to the .
the definítions of the other and quaternary structure
are ás above a The primary structure of a protein is the level of protein
levels are in such a position that the
Supersecondary structure is of structure are: specific sequence of amino acids. When two amino acids
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the next otlher, they can be combined by

association of secondary level, up from šecondary structure carboxyl groups of each amino acid are adjacent to each
structures. and involves, tne which results in the: formation of a peptide bond.
Domaiis are' larger associations Also known as structural motifs. undergoing a dehydration reaction
are linked by peptide bonds that begin with the N-
supersecondary elements, of two or more secondary
structures, two. or mo Amino acids in a polypeptide (protein) C-teriminal with a free carboxyl group. The
structures. They can
or mixtures of two
or terminal with a free amino group and ends at
also be kown as "folds, moré secondary and superseconu rotate freely due to a partial double bond character.
peptide bond is planar and cannot
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in Protein Tertiary Structure and 'modules. about peptide bond, there are two free
rotations on (N-
and contain between 35 domains are independently As we will see la While there is a restricted rotation
are called torsion angles, or more specifically
folding the phi and
acids. Note that some units of tertiary stru
and 200, ure (C-C) bond, which
slightly different definitions amino C) bond and limited due to steric
other authors may, pre rotation or these two bonds are also
in Protein Tertiary of the terms above and psi angles. The freedoms ot to make polypeptides with a defined amino acid
we will look
Strücture. at some definitions a hindrance. Genes carry the information amino acids in length, and some genes
Sequence. An average polypeptide is about u It's important to know the
are a few tnousand amino acids long.
encode polypeptides that
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the puuy
strueture cncodes
are
HTC
toretat
Corre
Correlale of
BIOLOGY
prvein brause structaun Ad function strand can Occur as parallel, anti-
y Strurturr ofthein their bivlogical tiuxT; parallel, or a mixture.

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npvrane configuration runs in tie same
functivnal orientation. Pleated Amino acid residues, in : para rallel
all levels ot biological organizaxta
alobular proleiis sheets. makes up
ad also are:dominant in.some fibrous the core of many
Protelns. The large aromalics proteins such as
. functions of secondary (MODEL QUESTION
such,as: tryptophan, tyrosirne a spiders web.
Describe the structure and rnino acids like ISoleucine, and phenylalanine,
and beta-branchea
conformations.This orienation is valine, and threonine. prefer
energetically less favorable to adopt -strana
Answer:
pnlyprptide, together wilh the laVS of
chemist vertical hydrogen bonds. rytophan, because of its slanted, non

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ne amino acid saquene of a and I tyrosine, and phenylalanine
into a mor compact structure. Amino acii car
acids the other amino acids are hydrophilics. are hydrophobics while
paysics. cause a poiypepiie tw fold are llexible and can c
This is the reason proteins
otate arourad bords within a avein.
or certain regions can have a repeat. 3. 8-turns: Poly peptid chains can change direction
inte a variety of shapes Folding can be imegular epeating by making reverse turns and
Loop regions that connect tWO anti-parallel p-strands loops.
folding patern. The coils ad folds that result from the hyarogen bonds between the are known as. reverse turms or j
repeaing sègmients or the poiypeptide backbone are calld secondary structures turns. These loop regions have irregular lengths
and shapes and are usually found.on the
Although tke individual hy erogen bonds are weak. Ihey are able to Support a specifie surface of the protein. The turn is stabilized by hydrogen
bond between the backbone of
shupe for that part of the pruein due to the fact that they are repeated many times over a carbonyl oxygen and amine hydrogen. The CO
group of the residue, in many reverse
long part of the chain ", Secondary structures of a protein are proposed by turns, which is bonded to the NH group of residue i
Pauling and +3. The interaction stabilizes abrupt
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Corey. Its strueturs àr iennd by amino acids that 'are located ithin short distances of changes in direction of the polypeptide chain. Unlike the alpha-helices and B-stands,
each ther. Serause of tie planar nature of the peptide:bonds, only loops do not have regular, periodic structures. However, they are usuallyrigid and
certain types of well
Secondar StTuture exist. The three important secondary tructures defined. Since they loops lie on the surface of the proteins, they are able participate.
are a-helix, B-sheets, t in
ard -tums. Alse. te beta sheets can be paralel, interactions between proteins and other molecules. Ramachandran plot is a; plot thát
antiparallel, or mixed: Antiparallel.beta
sheets are moe stable because the hydrogen shows the available torsion angles of where proteins can be found. However, in the plot,
bonds are at a ninety degree
helix is a ceied stucture stabilized angles. The a-
by intrachain hydrogen bonds,. if there. are many dots, that locate all over the place, it means that there exists a loup.
Characteristics ofthe
I. a-heli: In an a-helix.
Secondar Structures: 9. Describe the structure and functions of Tertiary& Quaternary Proteins.
the poly peptide backbone [MODEL QUESTION]
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that is stabilizei by forms a repeating

hydrogen bonds between a helical structure Answer:
These hydrugen bonds carbonyl oxygen. and an
occur at regular intervals amine hydrogen. Tertiary: As the secondary structure becomes established due to the primary structure, a
amind acid and cause of one. hydrogen
bond every fourth
helical stnucture is
the polypeptide backbone
to form a helix. The polypeptide folds and refolds upon itself to assume a complex three-dimensional shape
hydrogen bonds are
a right-handed helix
with its hydrogen
bonds
most common called the protein tertiary structure. Tertiary strueture is the overall shap of a
formed betweencarbonyl.oxygen parallel to its axis. The polypeptide. Tertiary structure resuits fróm the interactions between the side chains. (R
amino acid rasidues and amine
away. Each amino acid hydrogen groups of tour groups) of the -various amino acids. This three dimensional structure is due to
Each rurm of the kelix advances the helix,
is composed of 3.6 along its axis, by 1.S A. intramolecular, interactions between the. side groups along the polypeptide ,chain. Its
5.4 A. There is an amino acids; therefore
average domain typically contains 300 -400 amino acids, and it adopts a stable tertiary structiure
E

orientated outside of ten amino the pitch of the helix is

of the helíx. Different acid residues per helix with its when it is isolated from their parent protein. As a polypeptide folds into its functional
torming x-helix.
however proline amino acids side chalns
is a helix breaker have different propensities T shape, amino acids that have hydrophobic side chains tend to end up clustered at the core
amino group. Amino
acids that because proline
methionire, alanine, prefer to does not have a free of the protein so that they are out of contact with water. Covalent bonds called disulfide
leucine, glutamate adopt helical conformations bridges can also aíffect the shape of a protein. Disulfide Bridges form where two amino
and lysine (malek). in.proteins inCIu
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2. B-sheet: B-sheets acids containing sulfhydry! groups on their side chains are brought close together by how
are stabilized by hydrogen protein is folding. For some proteins, such as ribonuclease, the tertiary structure is the
et, regios
of the polypeptide
backbone come
bonding between the
final structure of a functional protein.. Other. proteins are composed of two or more
peptide strands. In
oge *ed d
by hydrogen
bonds.
he amine hydrogen The hydrogen bonds are
to lie parallel
to cach other anu
a polypeptides and adopt a quaternary structure.
means tnái the of amino acid formed between the carbo.
a-helix, and tnen:drogën bods are inter-stand. in adjacent strands in Quternary: While all proteins contain primary. secondary and tertiary structures,
distance berween f-shect regions a polypeptide. which quaternary structures are reserved for proreins Composed of two or. more polypeptide
adjacent amino are more extended
Chains. Proteins that have quaternary structures Contain more than one polypeptide and
acids is 3.5 A.
BIO-112 Hydrogen bonding"\ BIO-113
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caCh oter Va
via inte
intermoleeular
assenble Wiln strticture thaÍ is the
then the" overall
strueture and Sul BIOLOGY
polyieptiles a 11. What is Protein

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protein is
a tertiary structure of a denaturation? What
}t
1s. The quterary subuits. The mdividu.n sey;iratcly,Subunite e are the Conditions
forthat?
these polypeptide follcd be
e addition ofwhich means diterent pv»lypptules proleis consIst of more t Answera [MODEL QUESTION]
situnits, When One Protein denaturation: is the loss
Prcn or they may
be
ditlerent.
stricture id are also kn" own
protcins cxperience either the of native conformations of tertiary structure. Denaturing
ucncal iypeptidesthey an said tw have quaternary strur destruction of disruption
chain, ot mny prls. Qnernary structure. Denaturalion of internal tertiary or
pepde proteins consstunng
either:S secondary

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create however, does not break
multimerie proveins, meaning come together t0 Ait amino acids, thus not affecting the peptide bond between adjacent
thhn ow pntein ot a quaternary str
as u hen more structure the primary structure
Cin auso detined HectorViadiu. FHaemoglobin is an exiample however, will interfere thenormal of the protein. Denaturation
rimer. tetramer, etc. subunits. alpha-helix and beta sheets in
subunits and two eta ultimately distort its 3D shape. a protein which
that is cemposad of two alpa Denaturation causes the disruption of hydrogen
bonding between close proximity amino
the structure the Proteins. acids, thus interfering a protein's secondary"
10. State the factors which influence (MODEL QUESTION and tertiary structure. In tertiary structure
there are four types of bonding interactions
between "side chains" including: hydrogen
Answer: bonding, ionic bridges, disulfide bonds, and hydrophobic
their secondary, tertiary and intermolecular interactions.
Several tactors detennine the way that polypeptides adopt other words, there are several different conditions to denature
are the defining features the conformation of a
quaternary structures. The amino acid sequences of polypeptides
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protein.
that distinguish the structure of one protein from another. As polypeptides are
synthesized in a cell. they fold into secondary and tertiary structures, which assemble into Conditions that denature proteins:
quaternary structures for mest proteins. As mentioned, the laws of chemistry and physics, 1. Extreme pH (pH <4 or pH >
9): alters H-bonding
together with amino acid sequence. goverm this process. Five factors are critical 2. Heat (temp>70oC): thermal effect, disrupts weak forces non-covalent
for protein folding and stability: of
3. Detergents or organic solvents: disrupts hydrophobic interaction
bonds
1.Hydrogen bonds: Hydrogen bonds are formmed between a hydrogen bond donor and 4. Chaotropic agents (high conentrations): e.g., urea and guanidinium chloride
hydrogen bond acceptor. For amino acids. hydrogen bonding would
occur-between,the
backbone of the amine group and the oxygen of the carbonyl 12. What is DEAD box proteins?.
group. [MODEL QUESTION
2. Ionic bonds: Electrostatic
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interactions occur between two oppositely Answer:

molecules. lonic interactions are weaker in charged
water than in vacuum, this is due to a DEAD box proteins consist of RNA helicases, they are involved in RNA metabolism
ditferent dielectric constant faced in water between processes, and they are conserved in nine domains found in bacteria and viruses, to
opposing-charges within the proteins
structure. humans, They are 350 amino acids in length. DEAD box proteins are involved in pre-
3. Hydrophobic
effect: The hydrophobic interaction originates
from the tendency of non mRNA processing, splicesosome formation, and rearranging of ribonucleoprotein (RNP)
polar molecules to minimize
their interactions with water. complexes. DEAD box proteins are required in the pre-mRNA splicing and the in vivo
interact w ith water. these When non-polar molecuies
molecules tend to cluster splicing process. During the pre-mRNA processing, the DEAD box proteins unwind to
micelle. together in the center to Torm
provide energy to rearrange the five snRNPs (UI, U2, U4, U5, and U6) required in pre-
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4. Van der waals

forces: Van der waals forces exist mRNA splicing. In the in vivo splicing. three DEAD box proteins, Sab2, Prp28, and
close range. Of the three van der waals between non-polar molecui
at
interactions, interactions Prp5, are needed. Prp5 helps rearrange the conformation of U2, which allows the U2
dipoles is the strongest,
dipole-induced dipole between peria sequence bind to the branch point sequence. Prp28 helps the recognition of the 5' splicing
dipole and the London interactions are
dispersion forces'are the weaker than perma nent location,
between individual weakest. While
atoms are weak, the sum van der waals forces The first DEAD box protéin, the ElF4A translation initiation factor, are dependent on
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interactions between
many atoms in of van der waals forces resultinE from RNA ATPase, activity. This protein helps unwind the secondary structure, which stops the
sirength of van der waals large macromolecules The
interactions can be
maimal at the van der waals contact varies with the distance between substanad is
scanning.
5. Disulfide bridges: distance. the atomS
oxidation. These are
A disulfide bond can 13. Why all enzymes are proteins, but not all proteins are enzymes?
also the strongest be form bétween two cysteines through [MODEL QUESTION
covalent bonds within re
a protein's tertiary Su uct

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specific doorway designated for
it. Letters
as subsets. through the package door, and enter through the letter door; packages

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enzymes belong Speed post mail comes enter
Answer: molecules to which through the Speed post
larger set of function door
s is the
diverse in shape size
and 17. What is Passive and Active Cellular
Explunatio macromolecules that are witho Transport?
are biological reactions m a ving ccll Answer: [MODEL QUESTION]
Proteins that facilitate biological catalysts. There are two main kinds of cellular transport:
Enzymes are molecules passive transport and active transport.
i.e. these are so, make thoem
undergoing too much change changes and reversibly When passive transport occurs, molecules are

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moving from a concentrated area to a less
to undergo shape concentrated area. This doesn't require any energy;
The ability of proteins
enzymes among other things. the pressure in the concentrated area
most suited to function as are less suited for such a will naturally push molecules to the
area of lower pressure. The opposite
macromlecules like sugars and fats reason of this
Other bivlogical enzymes too. And tor the same- process, active transport, moves molecules from
molecules serve as a less concéntrated area to a. more
function. Somme RNA concentrated area. "This requires an input of energy in
the form of ATP, adenosine
too. triphosphate.
[MODEL QUESTION] Let's go back to the post office. Imagine there
14. How do proteins act as enzymes? are 100 postal workers inside the post
office and 20 workers outside. That'd be 100 molecules inside the cell
Answer: and 20 outside.
When workers from inside leave and go outside of the post office. they
Cells rely on thousands of different enzymes to catalyze metabolic reactions. Enzymes are moving from
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are proteins. and they make a biochemical reaction more likely to.proceed by lowering
an area with more workers (a higher concentration) to an area with less workers
(lower
the actis ation energy of the reaction. thereby making these reaçtions proceed thousands concentration). There's a lot morè rooim outside, so leaving the 'crowded post. office
or even millions of times faster than they would without a catalyst. Enzymes are highly requires very little energy. This is exactly how passive transport works.
specitic to their substrates. Ther bind these substrates at complementary areas on their On the other hand, if some of the workers on the outside decide to go into the post office,
surfaces. providing a snug fit that many scientists compare to a lock and key. Enzymes they would be moving from an area with less workers (lower concentration) to an area
Work by binding one or more substrates, bringing with more workers (higher concentration). They would need to exert energy to cram
them together so that a reaction can
take place. and releasing them once the reaction is complte. In themselves back into the crowded building. That's why active. transport requires energy
particular, when substrate
binding occurs. enzymes undergo a conformational shift from the cell.
that orients or strains the
substrates so that they are more reactive.
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18. What is receptor proteins? [MODEL QUESTION]

15. What is Transporter proteins? Answer:
Answer: [MODEL QUESTION] Receptor proteins are located within the cell surface membrane, nucleus membrane or
Transporter proteins constitute a other cellular organelle membrane. They can bind to corresponding ligands to initiate
significant fraction of membrane-bound
are typically expressed in proteins. "They cellular signaling pathways. For cell surface receptors, Such as receptor tyrosine kinases,
all organs involved in the uptake,
of drugs. including the gastrointestinal distribution, and elimination interleukin receptors and receptors of growth factors, they are usually subdivided into
kidneys. The sequence tract, the blood-brain
of many transporters is known. barrier, the liver, and tne three domains, extracellular domain, transmembrane domain and, intracellular domain.
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Receptor proteins form the largest family of biological targets.

16. Why the Transport
Proteins
are called as The Doors Examples of receptor proteins/receptors include: a. Guanine nucleotide
to the Cell? binding protein-coupled receptors (GPCRs) (metabotropic).
Answer: [MODEL QUESTIONJ]
Our cells are constantly
shipping and receiving
different types 19. What is the function of receptors in our body? [MODEL QUESTION]
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how a post office handles

Each cell has a plasma
various letters and packages. of molecules, similar Answer:"
and out of the cell. Eachmembrane, or a filter, that helps regulate Receptors are present in our all parts of the body for exanmple in skin, eye, nose tonigue
within it, which are plasma membrane has materials movin etc. They' detect the signals. and then send them to brain in the form of electrical
different transport
ued to
certain molecule to enter or help with this process. Each transport proteins einbeu signals. Receptors canbecome dystunctional temporarily or sometimes permanently
exít the cell. protcin only allow depending upon the level of exposure to a certain stimulus.
Think of these transport
proteins' as specialized
parcel each letter, doors of the 20. Describe proteins as structural unit. [MODEL QUESTION]
each package, and so on post office. Each type
may only enter
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the post officc throug" a

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amio acids,
which are all organic molecules
groun
group, a carboxyl
.
up, a METABOLISM

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Answer:
ofproteius sre atvm inkei to an amino
uilding blocks(central)
e an alpha
carha
covnnet calleda
side chan. information
nSIst ofatom, that starns win
the in
Chapter
gen ad a variadleof te daending pncess compose structural and
motor elemente at a Glance *

ane tie end prairts oell, proteins reaction tha

eins workhorses of te
euuar DNA. As serve as the catalssts for virtually
every biochemical
a startlinelu
cell, and tkey functions derives Trom The laws of thermodynamics are important unifying
principles of biology. These principles
the inernible array of

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In govern the chemical processes (metabolism) in
things. This all biological organisms. The First Law of
curs in living specities a hugely diverse
set of
structures.
structure. Not Thermodynamics, also known as the law of conservation
unique protein
contains the code for a sequences,
Simple coie that of energy, states that energy can neither
be created nor destroyed. It may change from
fact. each gene in cellular DNA
acid but they also are one form to another, but the energy in a closed
In
2ssemblad with different amino three-dimensional.structures system remains constant.
only are these proteins variety of The Second Law of Thermodynamics states that
bonis and folded into a sequence of when energy is transferred, there will be less
held together by ditferent depends directly on the linear amino acid 2nergy available at the end of the transfer process than
contormation, at the beginning. Due to entropy, which is
The folded shape. or he measure of disorder in a closed system, ail of the available energy
will not be useful to the
the protein organism. Entropy increases as energy is transferred.
n addition to the laws of thermodynamics, the
cell theory, gene theory, evolution, and
omeostasis form the basic principles that are the foundation for the study of life.
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Multiple Choice Type Questions
1. Catalysts: [MODEL QUESTION]
a) increase the activation energy
b) are used up in reactions
c) provide an alternative reaction pathway
d) slow down chemical reactions
Answer: (c)
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2.Which of the following is not a feature of collision theory? [MODEL QUESTION]

a) the rate of chemical reactions increases with inereasing temperatures
b) the reaction is faster in dilute solute solutions than in concentrated
c)at high temperatures molecules have more energy than at low temperatures
d) the more molecules present, the faster the reaction
Answer: (b)
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3. Examples of anabolic reactions include: [MODEL QUESTION]

a) the breakdown of lipids b) the breakdown of carbohydrates
) hydrolysis reactions d) the build up of proteins
Answer: (d)
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4. The conversion of glucose to carbon dioxide and water is an example of

[MODEL QUESTION]
) a catabolic reaction b) a condensation reaction
c) an esterification reaction d) an anabolic reaction
Answer: (a)

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surroundings
exergonic reactionfrom the being broken d) all of the above

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5. In an absorbed strength as bondsbroken
aenergyis formed are the same bonds being Answer: (d)
being stronger than
D bonds being formed are
CDonds surroundings 13. During. catabolism, only about 40%
the
energy is released to of the energy available from. oxidizing
d) glucose is used to synthesize ATP. Remaining
Answer: (d) MODEL QUESTION a) is lost as heat 60% MODEL QUESTION]

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reaction: being broKen b) is used to reduce NADP
6. In an endergonic bonds
being formed are stronger than c) remains in the products of metabolism
a bonds
energy is absorbed from the
surroundingS
as bonds-being
broken d) is stored as fát
b) strength
are the same Answer: (a)
bonds being fomedto the surroundings
d) energy is released
Answer: (b) 14. Why does the glycolytic pathway continue in the direction of glucose
water then right hand side of that catabolism? [MODEL QUESTION]
equation is ADP +
7. If left hand side of chemical [MODEL QUESTION] a) There are essentially three irreversible reactions that
act as the driving force
chemical equation is equal to for the pathway
b) APM+ Mi+ energgy
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a) AMP+ P+ energyY b) High levels of ATP keep the pathway going in a
c) BMP+ B;+ energy
d) TDA + T+ energy forward direction
c) The enzymes of glycolysis only function in one directipn
Answer: (a) d) Glycolysis occurs in either direction
Answer: (a)
8. Majorsource of energy to perform cellular functions such as exocytosis,
endocytosis, movement and transmission of nerve impulses, is 15. The released energy obtained by oxidation of.glucose is stored as
[MODEL QUESTION] .
a) ATP b) BTP c) PTA d) APT [MODEL QUESTION]
a) a concentration gradient across a membrane
Answer: (a) b) ADP
".

c) ATP d) NAD
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9. Biologist who discovered ATP is Answer: (c)

[MODEL QUESTION]
a) Daniel Olive b) Daniel Koshland 5. kinase is an enzyme [MODEL QUESTION
c) Karl Lohmann d) Emil August that
Answer: (C) a) removes phosphate groups of substrates
buses ATR to add phosphate
a group to the substrate
10. Nobel Prize winner biologist c) uses NADH to change the oxídation state of the substrate
who. proposed ATP as major d) removes water from a double bond
molecule in cells is energy-transt
a) Fritz Lipmann [MODEL QUESTION] Answer: (6)
b) Emil August
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c) Daniel Koshland
Answer: (a) d) Karl Lohmann 17. Kreb's has been awarded Nobel Prize in 1953 for explaining
[MODEL QUESTION]
11 Nobel Prize winner Fritz Lipmann a) Energy forming process in the cell b) ATP metabolism
molecule in cells in who proposed ATP c) Respiration chain d) Oxidation of cytoplasm
as major energy-tran fer
Answer: (a)
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a) 1949 b)1935 [MODEL QUESTION

Answer:(C) c) 1941
d) 1929 18. The product formed by maleic dehydrogenase is [MODEL QUESTION]
12. Glycolytic pathway a) Maleic acid b) Fumaric acid
regalation involvees
a) allosteric stimulation c) Oxaloacetic acid d) Succinic acld
b) allosteric inhibition by ADP [MODEL QUESTIONJ Answer: (c).
by ATP
c) feedback, or product,
inhibition by ATP

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pyruvic acid is

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carboxylaso, [MODEL QUESTION for cxample, perlorm a number
presence of TPP and In photosynthesi, the energyof important processes. These processes,
1n b) Ethyl
alcohol and CO is supplied by the sun. require energy
plant leaves and converted to Light energy is absorbed
a) Acetaldehyde
and CCo%
d)None of the above chemical energy, by cells in
of glucose, which is used to form complex The chemical energy stored
c) Citric acid and CO2
The enerEy stored in glucose carbohydrates necessary is in the form
can also be released to build plant mass.
Answer: (a) process allows plant and animal through cellular respiration.
MODEL QUESTION This

AU
organisms to access the energy
lipids, and other macromolecules
Indirect oxidation pathway
stored in carbohydrates,
20. TCA cycle is a b) through the production
of ATP. This energy.is needed
a) Direct oxidation pathway d) None of the above
to perform cell functions such as
DNA replication, mitosis,
c) Both [a] and [b] endocytosis, exocytosis, and apoptosis. miosis, cell móvement,
Answer: (b)
[MODEL QUESTION] 2. State the importance second law of Thermodynamics
21. Hydrogen of malate is accepted by d) CoQ
in Biological Systems.
a) FAD ) FMN c) NAD IMODEL QUESTION
Answer:
Answer: (C) As with other biological processes, the transfer energy
of is not I00 percent efficient. In
(MODEL QUESTION] photosynthesis, for example, not all of the light energy ís
22. Which of the coenzyme is used in acetylation reaction absorbed by the plant. Some
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c) FMN d) None of the above energy is retlected and some is lost as heat. The loss
a) CoA FAD of energy to the surroundingg
environment results in an increase of disorder. or. entropy. Unlike plants
Answer: (a) and other
photosynthetic organisms, animals cannot generate energy directly from .the
sunlight
They must consume plants or other animal organisms
23. Ferredoxin is a [MODEL QUESTION] for energy. . .

a) Protein b) Fat c) Phenol d) None of the abov The higher up an organism is on the food chain, the less available energy it receives from
Answer: (a) its food sources. Much of this energy is lost duting metabolic processes performed by the
producers and primary consumers that are eaten. Therefore, much less energy is available
for organisms at higher trophic levels. (Trophic levels are groups that help ecologists
24. Which intermediate compound is involved in the synthesis of amino acids
[MODEL QUESTION understand the specific role of all living things in the ecosystem.) The lower the available
M

a) Malic acid b) Citric acid energy, the less number of organisms can be supported. This is why there are more
c) a-ketogluteric acid d) Isocitric acid producers than consumers in an ecosystem.
Answer: (c) Living systems require constant energy input to maintain their highly ordered state. Cells,
for example, are highly ordered and have low entropy. In the process of majntaining this
25. In ATP molecule energy is stored in order, some energy is lost to the surroundings or, transformed. So while cells are ordered,
[MODEL QUESTION
a) Chemical bonds b) Hydrogen bonds the processes performed to maintain that order result in an increase in entropy in the
c) Carbon bonds
d) Pyrophosphate bonds cell's/organism's.surrOundings. The transier of energy causes entropy in the universe to
Answer: (d) increase.
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26. The process by which the energy of glucose is [MODEL QUESTION]

3. What is exothermic and endothermic reaction?
respiration was discovered by released under aerou
[MODEL QUESTIONI. Answer:
a) Hopkins b) Lister heat, causing the. temperature of the immediate
Answer: (c)
C) Kreb's
d) Pasteur
"

An exothermic process' releases

surroundings to rise. An endothermic process-absorbs heat and cools, the surroundings.
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Many chemical reactions release energy in the fom of heat, light, or sound. These
Short & Long Answer Type aré exothermic reactions. Exothermic reactions may occur spöntaneously and result in
Questions | higher randomness or entropy (AS' > 0) of the system. They are denoted by a negative
1. State the importance of first Law of Thermodynamics
in Biological Systems.N heat flow (heat is lost to the surroundings) and decrease in enthalpy (AH <0). In the lab,
[MODEL QUESTION reactions produce heat or may even be explosive.
Answer: exothermic
All biological organisms require energy
to survive. In
universe, this energy is not consumed out transformed a closed svstem, such as
from one form to another. BIO-123
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energ n orucr. to
reactions that
must adsord
cannot oceur
. CSe
spontaneously Work
BIOLOGY

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Answer
are other ehemical Endothermic reactions endotherinic reactions bsorb An exergonic-reaction is always acompanied
here reactions. When
re endothermie reactions to occur. Endotherm
hermic reaction are That means, delta G Is always negative.
by a decrease in free energy
of the syste
in order to get these during the reaction. Most
delta H (change in enhalpy) is also negative. of such reactions
must be done measurd are exothermic; that
temperature dnop is an increase in enthalpy (+A
+AH). is,
cerg. a reaction) and
flow (into the Changes in free energy (G ), enthalpy (
characterized by positive heat = H) and entropy (S) are related by the equation:
[MODEL QUESTION] delta G delta H -T. delta S.

4. What is exergonic
Answer:

on the relative
and

When a chemical eaction

strengths
In an exergonic reaction,
endergonic reaction?

of
takes place energy is
bonds
either taken in or released.
being broken and
bonds.being formed.
energy is released to the surroundings.
are stronger than the bonds being broken.
In an endergonic reaction.
I ne
This dene

bonds being formed

energy is absorbed from the Surroundings. The bonds beino

formed are weaker than the bonds being broken.
rmed
AU
So, even if delta H is positive (endothermic).
delta G can be negative, provided delta S
is also positive with a large value for T (temperature). In
energy is still possible even if there is absorption heat.
of
also be an exergonic reaction under certain conditions.

8. State the Relationship between free Energy and Equilibrium

Answer:
other words, decrease in free
So, an endothermic reaction can

Constant.
[MODEL QUESTION]
The free energy change of the reaction in any state, AG (when equilibrium has not been
AK
5. What is metabolism and metabolites?
[MODEL QUESTION attained) is. related to the standard free energy change of_the reaction, AG" (which is
Answer: equal to the difference in free energies of formation of the products and reactants both in
Countless chemjeal reactions take place in cells and are responsible for all the actions of their standard states) according to the equation.
organisms. Together. these reactions make up an organism's metabolism. The chemicals AG= AG° + RT InQ
taking part in these reactions are called metabolites.
.

In all reactions:
Where is the reaction quotient
When equilibrium is attained, there is no further free energy change i.e. AG =0 and
chemical bonds in the reacting molecules are broken; this takes in energy
new chemical bonds form to make the products; this gives out energy becomes equal to equilibrium constant. Hence the above equation becomes.
When a chemical reaction takes place energy is either taken in or
released. This depends AG=-RTIn K(«)
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on the relative strengths of bonds being broken and

bonds being formed.
Of, AG = -2.303 RT log K(ea)
6. What are the differences between Exothermic reaction and
Exergonic reaction [MODEL QUESTION]
[MODEL QUESTION 9. What is the Spontaneity of Chemical reaction?
Answer: Answer:
I. Exothermic reaction
a. Energy releásed is just called energy
In general, the spontaneity of a process only determines wiether or not .a
process can occur ånd makes no indication as to whether or not the process will occur. In
b: Energy of reactants is
greater than that of products. other words, spontaneity is a necessary, but not suficient. condition for a process to
E

CEnergy of the reaction system. decreases actually occur. Furthermore, spontaneity makes no implication as to the speed at which as
.e. the surrounding becomes.hotter. relative to that of the surrounang
spontaneous may occur.
2. Exergonic reaction
As an example, the conversion of.a diamond into graphite is a spontaneous process at
EnergY released, has a special name room temperature and pressure. Despite being spontaneous, this process does not occur
energy called Gibbs energy or GIDOSGibbs free Since the energy to break the strong carbon-carbon bonds is larger than the release in free
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b. Energy reactants energy.

is greater than that ot
C.lt has nothingto the products
do.with how hot or cóld reactants
chemical meaning-t become. Has more 10. How to determine spontaneity of a chemical reaction Using free energy
means that a reaction relates to the spontaneity of the reaction; ays [MODEL QUESTIONI
is feasible, i.e. reaction thus it a
will always happen.
7. Can endothermic reaction also
be an exergonic reaction?
[MODEL QUE
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pressre, Sponlaneity can he
teyvrature nt by:
Answer:
Answer costan

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that oarus at nhich is given
frer energy.
in enthalpyy (AlN
NH2
prNess in Gibhs ch:anges
negaive (or vice v.
the change signs ot the
using the sign vi MG
depenis vn the
chnge Irom
positiNe to versa)
herentropY (.LS). The sign of M uill
I)-
N
d P-0-
Where T

AU
OH OH OT
toriward direction.
In cases where 3G is spomanaus and may proceed in tne as
egative. the paness is
out may procee
written.
the praves is
non-spontaneous as Writen, I
OsItie.
Spentanevusly in the reverse direction. place over time. O
equilibrium. with no net change taking ATP Adenosine triphosphate is a nucleotide, which is
2er. tne prres at
is
four distinct cases by examining the
signs of mainly composed of the
This set ot rules can euad to dètemine molecule adenosine and three phosphate groups. It is
soluble in water and has a high
the AS and AH. energy content, which is primarily due to the
spontaneous as written. presence of two phosphoanhydride bonds
AK
whenS>0 and AH <0. the process is always connected to the three phosphate groups.
When AS s 0 and AH> 0. the process is never
spontaneous, but the reverse
The triphosphàte tail of ATP is the actual power source which
the cell taps. The available
precess ts aiuays spontaneOus. energy is contained in the bonds between the phosphates
and is released when they are
When AS and AH> 0. the process will be spontaneous at high temperatures
>0 broken or split into molecules. This ocurs through
the addition of a water molecule
nor-Spontaneous at loW temperatures
and (hydrolysis). Usually, only ,the outer phosphate group is removed from
When AS<0 and aH< 0. the process will be spontaneous at low temperatures energy; when this occurs, ATP Adenosine triphosphate ATP to yield
-
is converted into ADP
and ron-spontaneous at high temperatures. adenosine diphosphate, it is the form of the nucleotide having only two
For the latter two cases. the temperature at which the spontaneity changes will be
phosphates.
ATP molecules are largely composed of three essential components.
detenined by the reiative magnitudes of AS and AH. The pentose sugar molecule i.e. ribose sugar.
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'Nitrogen base- Adenine, attached to the first carbon of this sugar molecule.
11. What is ATP- Adenosine Triphosphate? TMODEL QUESTION] The three phosphate groups which are attached in'a chain to the 5th carbon of the
Answer: pentose sugar. The phosphoryl groups, starting with the group closest to the
ATP- Adenosine triphosphate is called the. energy currency of the cell. ribose sugar, are-referred. to as the alpha, beta. and gamma phosphates. These
It is the organic compourd composed
of the phosphate groups, adenine, and the sugar phosphates play an important role in the activity of ATP.
ribose. These moecules provide energy for various biochemical
processes in the boay.
Therefore. it is called "Energy Currency of the 13. How is energy produced by the ATP molecules?
Cell". These ATP molecules arc [MODEL QUESTION]
sy nthesized by Mitochondria, therefore
E

it is called powerhouse of the cell. Answer:

The ATP molecule was discovered in the The three phosphate groups present in this ATP molecule are called high energy bonds as
year 1929 by German chemist Karl Lohman.
Later in the year 1948, Scottish biochemist they ire involved in the liberation of a huge amount of energy when they
synthesized the ATP molecule.
Alexander Todd was' the first person are broken. This
moleeule provides energy for various life processes without which life cannot exist.
ATP- the energy-carrying molecules are found .. It is used by various enzymes and structural proteins in cellular proçesses like
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in the cells of all living things. Thes

organic molecuies tunction by capturing biosynthetic reactions, cell divisions. etc. This "energy currency of the cell" is produced
food molecules and are Jater released the chemical energy obtained
from the aig during cellular respiration where a digested simple molecule of food is utilized.
for different cellular processes.
Once atter the energy is produced by theATP molecules. tlhey are stored in its bonds
12. Describe thestructure of Structure which are later utilized by.the cells by breaking the bonds whenever required
of ATP molecule. [MODEL QUESTION]
14. What are the Functions of ATP? [MODEL QUESTION]

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transporlation of dilferen
din
tiunetioNs. inctuting ND2

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Answer: various cellular
tunctions ot ATP
include supplying tio energy Adenosine
e ATP is used for
across cell membranes. Other circulation, and various triphosphate
C Adenosine
molecules for the, blood
tor the muscle vontrastion, fhonm energy production includes: triphosphate HLaN
requred
movements. A signitieant role
ot ATP apart the cell requiree to
types of macromolcules that
Synthesizing the multi-thousands of control chemical, reactions and to send
switch to +HPO +H.

AU
as a
exist. ATP molecule is also used
'.mesSIges.
in Metabolism? MODEL QUESTIONI HO :
OR
15. What is the Importance of ATP Molecule ATR 10 DH

Answer: .
ADP
1. These ATP molecules can be recycled after every reactjon. ..'
the energy
ATP molecule provides energy tor both the exergonic arid endergonic
processes. The conversion of ATP to'ADP yields about 7.3 kcal/mol of energy: This is
ATP serves as an extracellular signalling molecule and cts as a neurotransmitter SOurce. in a variety of biological processes occurring in both plants and animals
(i) Store small
in toth centrai and peripheral nervous systems. Justification for. the term energy currency' for ATP can be given as
its. wastage. (i1) Can make
packets of energy.as sõon as it is available. thu, minimising
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4. It is the only energy. ivhich can be directly used for, different metabolic process. is produced. (iii)
Other forras of chemical energy need to be converted into ATP before they can energy ayailable to a.distant location in.cell away from where;the site it
large amount :of energy
e used. Cán carry out: heayy. work/activity by, continuously upplying
5 t plays an important role in the Mctabolism+ A life-sustaining chemical through its accumulation at one place.
reactions including cellular division, fermentation, photosynthesis, [MODEL QUESTION]
photophosphorylation, aerdbic. respiration, protein synthesis, exocytoSI5, 18. Do plants breathe?
endocytosis and motility. Answer: : to occur and they also give out CO2. Hence, plants have
.Plants:.require O2.for respiration
16. Why ATP is ensure the. availability of O2. Plants. unlike animals, have no
called energy currency.of the cell?
[MODEL QUESTION] systems in place that
stomata and lenticels. for this
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Answer: . specialisd organs for gaseous exchange but they: have respiratory. organs.
All'activities inside a living cell need energy
which is aväilable in purpose. There are several reasons why plants can get along without little
immediate source. nce, ATP.is, described as, the form of ATP as plant part takes care of its own gas-exchange needs. There is very
"The Energy Currency of tne First each gases not present great
When energy in form of ATP used,
is the ATP is converted transport of from one plant part to another. Second. plants do. animals
energy is available by further breakdown to ADP and again when n Roots, stems and, leaves respire at rates far lower than
of glucose, the ADP is reconverted demands for gas exchange. gases exchanged and, each leaf is
so it goes on. One mole of to AI*and Only' during photosynthesis are. large volumes ot
Thus. ATP provides energy
on
glucose complete oxidation yields
38 molëcules of
do. -care of} its owh needs during these. periods. When cells
whenever,WDerever
and howeverit Al well: adapted to take a problem in these cells since O2 is releasedis
photosynthesise, availability of O2 is not

.
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is.needed.
17. Explain the term "energy Third, the distance that gases must ditfuse even in large. bulky plants
currency? within the cell. plant. This.
in plants.and animals? Which substance rrency
acts as energy cuONi not great. Each living cell in a plant is located. quite close to the surface of thé
Answer: MODEL QUESTION leaves'. you may ask, "but what about thick, woody stems and roots?' In stems:
The term energy currency
is true for
layers inside and beneath the bark. They also have
reiers to tnat molecule the living' cells are organised in thin are dead and provide only mèchanical.
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2ctivities, whenever sequired.

AlF IS
which provides.energy:
10r openings called lenticels. The cells in the nterior
preseit the form of high energy emed as energy currency because s a part of their surface in contact with air.
Support. Thus. most cells of a plant have at leastof parenchyma
bonds of ATR the are cells in leaves. stems and
GTP. CT? LTRetc. other energy yiclding molecules This is, also facilitated by.the loose packing
roots: which provide an interconnected network ot air spaces. The complete combustion
and H20 as end products. yields.energy mast of whiçh
is
of glucose, which produces c02
BIven out as hea.

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+oll.0+Energy Step 1: Hexokinase
6CO, to utilise it to
synthesise
CHO. +60,usetul to the cell, t should be able a
l
cell uses
usesis

TI
to be strategy that the plant
is to catabolige
this energy is rquires. The goes óut IC-OI1
lf
molecules thx the cell thau nvtall the [iberated energy
ènabling Some
enabling
The
ke
IC-O
sueh a way
glucose molerule in several smail steps steps
t hexokinase
step but im
to onidise glucose nat in one released can be coupled to ATP
H OH du Mg
Is
Just large eneugh such that the
the
enerE
story of respiration. During the process ofs OH O OH

essentially. energy are released as

AU
OH
this is done is. dioXIde. water and
0xygen is utilised,
and carbon
some cells inve Where
oxygen may or Glucose
Glucose-6- phosphate.
oNygen But
comoustion reaction requires (and organisms) where O2 is not r availabe phosphate group
think of such situations
be availabie. Can you Iirst cells on this planet liv
lived in
believe that the
There are suficient reasons ta knou
among present-aay. Iiving organisms, we
atmespher that lacked oxygen. Even are faculha -P-U
Some OT tnese organisms
severai that are adapted to anaerobic conditions.
is obligate. In
anaerobes. while in others the requirement for anaerobic condition
The first step in glycolysis is the conversion of D-glucose into glucose-6-phosphate. The
case. all-iving organisms retain the enzymatic machinery to partially: oxidise gluu enzyme that catalyzes this reaction is hexokinase.
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without the help of Oxygen. This, breakdown of glucose to. pyruvic acid. is cale

glycolysis.. Details:
Here, the glucose ring is phosphorylated. Phosphorylation is the process of adding a
phosphate group to a molecule derived from ATP. As a result, at this point in glycolysis,
.

19. What is glycolysis? Describe the different stages of glycolysis.

*

[MODELQUESTION molecule of ATP has been consumed.

Answer: The reaction occurs with the help of the enzyme hexokinase, an enzyine that catalyzes the
phosphorylation of many six-membered glucose-like ring structures. Atomic magnesium
The term glycolysis has originated from the Greek words, glycos for sugar, and iysis e
is also involved to help shield the negative charges from the phosphate groups on
spliting. The scheme of glycolysis was given by Gustay Embden, Otto Meyerhot, an
Parnas. and is often referred to as
, (Mg)
the ATP molecule. The result of this plhosphorylation is a molecule called
glucose-6-
the EMP påthway. In anaerobic organisms, the
phosphate (G6P). thusly called because the 6 carbon of the glucose acquires
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only process in respirarion. Glycolysis occurs. in the cytoplasm l

in all living organisms. In this process, glucose of the cell and is l phosphate group.
undergoes partial oxidation
molecules of pyruvic acid. In plants,
this glucose is derived
t0 is te Step 2: Phosphoglucoselsomerase
end product of photosynthesis, from sucrose, W ich
or from storage carbohydrates.
glucose and fructose by
the enzyme, invertase, and Sucrose. 1s.CO verted i
reao
these two monosaccna HCO
enter the gycolytic pathway.
Glucose and fructose
phosphorylated
o- H HC-OH
glucose-6- phosphate are to H
O
enzyme hexokinase. This pnorl
by the activity of the
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fom of glucose then isomerises

metabolism to produce fructose-6-
of glucose and fructose are: same. phosphate. SuDscreaci
ees
.
OH /oH
132
Phosphoglucose isomeras
OH
4T
under the control of OH
different enzymes, takes
In glycolysis,
a
chain oracose.
place to produce pyruvate
OH

luc Glucose-6 Fructose-6

iro
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phosphate phosphale

6-phosphate (G6P) into

The seconid reactionof glycolysis IS the rearrangement of glucose
6-phosphate (F6P) by Blucose piospnare isomerase (Phosphoglucoselsomerase).
fructose
Details glucose-6-phosphate to
invoives tne conversion of
The second step of glycolysis With the help of the enzyme
fructose-6-phosphate (F6P). Ihis reacOn occurS
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name of the
enzyme
suggests
ests, this BIOLOGY
phosphoglucoseisomerase (Pl). As the reacti
reaction. Step 4: Aldólase
involves an isomerization

TI
rearrangement of the carbon-oxygen bond to transfn.
The reaction involves the
membered ring into a five-membered
ring. To rearrangement takes place wlhe PO-CH
in such a way that the first carbon bencomesnoa
HCOP
membered ring opens and then closes
HOH
external to the ring. OH
Fructose-1,6 /

AU
bisphosphate OH H
Step 3: Phosphofructokinase
.
Aldolase
A
Glyceraldehyde-3.
OH -CH HC-O Dihydroxyacetone
phosphate (DHAP). phosphate (GAP)

H
OH Mg ot OH H A

HC-0
OH H
C:0 HCOH
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Fructose-6
+AD+ H H
Fructose-l,0- HO-CH HG-OR
phosphate
bisphosphate .
H

Phosphofructokinase, with magnesium

fructose .6-bisphosphate. as a cofactor, changes fructose 6-phosphaie
l Iriosphosphate
ISomerase (TIM)
Details:
In the third step of glycolysis,
bisphosphate (FBP). Similar fructose-6-phosphate
is converted to fructose e enzyme Aldolase splits fructose.1, 6-bisphosphate into two sugars that are isomers of
(DHAP) and
molecule of ATP provides
to the reaction that occurs
in step 1 of glycolysIS, a seco ch other. These two sugars are dihydroxyacetonephosphate
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the phosphate group that yceraldehýde 3-phosphate (GAP).

The enzyme that catalyzes is added on to the
magnesium atom is this reaction is phosphofructokinase F6P moieeu etails:
involved to help shield (PFK). AS I ** step l cleavage. of FBP to yield two
negative This step utilizes the enzyme.aldolase, which catalyzes the
charges. is called lyceraldehyde-3-phosphate (GAP)
carbon molecules. One of these moleçulesphosphate (DHAP).
nd the other is called dihydroxyacetone

Step 5: Triosephosphateisomerase Glyceraldehyde-3-

Dihydroxyacetone
E

phosphate (DHAP)
phosphate (GAP)

-O CO
HCOH
HO
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HO-CH
H.

Triosphosphate
ISomerase(TIM)

triosephosphateisomerase dpdy nter converts the molecules

The enzyme gyceraldehyde 3-phosphate (GAP).
dihydroxyacetone phosphate (DHA Useand in next step of Glycolysis.
removed/
lyceraldehyde phosphate is
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prUnway. As a resul BIOLOCY

Details: in the glycolytic ;ut.first
that continues iriosephosphat of molecule of AlP. Since we
GAP is the only molecule by' the enzyine (hecausé there were two actually have two

TI
are further
acted on in glycol molecules of 1,3bisphoglycerate
DHAP molecules produced G:AP so it can continue lysis. 3-carbon products from
DtHAP into A Synthesize two molecules of ATP stage I
of glycolysis). we actually
). which reorganizes the 3-carbon molccules, ave not
but have
yet fu cancelled the'first two molecules
at this step. With this
synthesis of ATP, we have
in the glycolytic pathway.
we have two of ATP that we used, leaving
Ont molecules up 1o this stage of glycolysis. us with a net of 0 ATP
Converted glucose into pyruvate.
Again, we see tnat an atom, of magnesium is
Dehydrogenase involved to shield the negative charges

AU
Step 6: Glyceraldchyde--phosphate the phosphate groups of the ATP molecule. on

Gheeraldehyue 1,3-bisphoglycerate
phsphate (iAP) Step 8: PhosphoglycerateMutase
3phosphoglycerate
2 phosphoglycerate

HC-OH +NAD+ HC-O CFO

GAPDII HC-O TIGOl
H HGOB phsophoglycerate
iICO
H
C-OH
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+NADH +1 mulase
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) dehydrogenates
inoryganic phosphate to glyceraldehyde 3-phosphate,
and adds The enzyme phosphoglyceromutase relocates the P. from 3- phosphoglycerate from the
producing 1, 3-bisphosphoglycerate 3rd carbon to the 2nd carbon to form 2-phosphoglycerate.
Details:
In this step. two main Details:
events take place: 1) glyceraldehyde-3-phosphate is oxidized
coenzyme nicotinamide adenine dinucleotide by th This step involves a Simple rearrangement of the position of the phosphate group on the
(NAD); 2) the molecule is phosphorylated phosphoglycerate molecule, making it 2 phosphoglycerate. The molecule responsible for
by the addition of a free phosphate
group. The enzyme that catalyzes catalyzing this reaction is called phosphoglyceratemutase (PGM). A mutase is an enzyme
glyceraldehyde-3-phosphate dehydrogenase this reaction is
(GAPDH). that catalyzes the transfer of.a fünctional group from one position on a molecule too
The enzyme GAPDH contains
M

appropriate structures and holds another.

conformation such that it allows
the NAD molecule to pull
the molecule in a
converting the NAD to NADH.
The phosphate group
a hydrogen off the GAP, .The reaction mechanism proceeds by first adding an additional phosplhate group to the 2
releases it from the enzyme then attacks the GAP molecule and position of the 3 phosphoglycerate. The enzyme then removes the phosphate from the 3'
to yield 1,3bisphoglycerate, position leaving just the 2" phosphate, and thus yielding 2 phsophoglycerate, In this way,
NADH, and a hydrogen atom.
Step 7: Phosphoglycerate the enzyme is also restored to its original, phosphorylated state.
Kinase
1.3-bisphoglycerate
3
Step 9: Enolase
phosphoglycerate
o 2-Phosphogiycerate
E

Phosphoenolpyruvate *

HG--OH PGK
ADP
H OD MgHC-Ol +ATP
0

u-O C-OP
Enclose
AR

COP + HO
H
Phosphoglycerate kinase IIC-OU TIC.
(water)

ADP to torm ATP transfers a phosphate

and 3-phosphog)ycerate. group from 1,3-bisphosphogiyca
Details: H
In this step. :The enzyme enolae removes a, molecule of water from 2-phosphoglycerate to
1.3bisphoglycerate form
phosphoglycerate is converted phosphoenolpyruvicaçid (PEP).
kinase (PUK). This to 3-phosphoglycerate enzyme Details:
from the starting reaction involves by arou
material. he phosphate This step involves the conversion or phosphogiycerate to phosphoenolpyruvate (PEP).
is transferred the loss of a phospi vjeld The. reaction is catalyzed by the enzyme enolase. Enolase works by renmoving a water
to a molecule of
BIO-134 AD ua BIO-135.
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The
specilicny, O the cn7
1zyme
phosphoglycer.ate. cova POci or ne cycie. are a series
the 2 STeps too
COnpicatcd oto cover here. he eight steps of redox, dehydration, hydration, and
Tup. or.iby ovcur through a serics
oI ecarboxylation reactIons nat produce two carbon dioxide molecules.
one GTP/ATP. and

TI
for tie vaction ed
to forms of NADH and FADH2. This is considered an
oS reduc aerobic pathway because the
JADH and FADH2 produced must transfer their electrons
NA to the next pathway in the
Step 10: Pyruvate Kinase Pyruvate cVstem, which will use oxygen. tt this transfer does not occur,
the oxidation steps of the
F'nesphvenlps ruv ate itric acid cycle also do not occur. Note that the citric acid cycle produces very little A
directly and does not directly consume oxygen.

AU
C-

CE0 ,+ADP . CoA

COO
ADI *
piruvate kinas CH-CS CH
HCL
CO0
HO=CCOO
Acetyi CoA
The enzyme pyTuvate kinase transfers aP from phosphoenolpyruvate (PEP) to AD
COO COo
ienn pyruvit acid and ATP Result in tep 10. COO C0
AK
SH-C.
HO-CIl NADHH1 c| u-
HC-coO
Details:
.

Oxaloacetate Citrate
The iinai stepof glyeolysis converts phosphoenolpyruvate ino þyruvat with the helpof NAD HO-CH
e enzye pYTU ate kiase. As the enzyme's name suggests, this reaction involves the ,
COO COO
trans?er er a phosphate group. The phosphate group attached to, the 2' carborn of the PEP Isocitrate
S

trans teed to a molecule of ADP, yielding ATP. Again, since there are two molecules Malate NAD
of PEP. rere we actually generate 2 ATP molecules. NADHH
Steps i an<3 =-2ATP COO CO:

. CO0
M

Steps 7 and i0 = 4 ATP

-

Net visible" ATP produced= 2. a-Kefoglutarate,

Lmimediateiy upon finishing glycolysis, the Fumarate NAD
cell must continu .respiration in ether an SH-CoA
aerobic or anaerobic direction; this choice is
made bäsed on the circumstances of e
particuiar celt. A cell that can perförm aerobic respirátion
and which finds itself in tne
FADH:
C NADHH
CO
.
CH2

presence of oxygen will continue on

It a cell able to perioFm aerobic
to the aerobic citric acid cycle. in
the mitochond
9FAD ccin:
7
Succinyl CoA
COO
respiration is in a situation QH P
no O COO
under extreme exertion), it will move where there is,
.
(such as muscles G
E

GDP
respiratiorn called homolactic into a type ot .anae obIe SH-CoA
CH:
fermentation. Some cells
out aerobK respiration such as yeast are unable'to
and will automatically move
called atcoholic fermentation. a
into type of anaerobic resp* CH:

.CH
AR

20. What is Citric Acid

Answer:
Cycle?.
[MODEL QUESTION coo
Tricarboxy iic Atid Cycle or
Like the conversion o
Citric Acid Cycle or Krebs Cycle, 41. Define Citric Acid Cycle. Explain all the steps of Citric Acid Cycle.
pynuvate to acetyl CoA, [MODEL QUESTION
matnx ot the mitocnondria. the citric acid.cycle
Aimost all of the enzymes tákes pla ble
With the singie of the citríc Answer:
exception or ne enzyme sucçinate acid cycle arcAed 'Ihe cycle:.ln the citric acid cycle. the acetyl group from acètyl CoA is attached
the inner membrane of dehydrogenase, whichisis enbedded i The acid eyc
citric acid
molecule. Through a
closed loop: the last partthe mitochondrion. Unlike emois
cycle 15 tour-carbon oxaloacetate molecule to form a siX-carbon citrate
0 to a tour-carbo
ot thne paunway e glycolysis,
gycolysis,
regenerates the compound
the citric acid
citric acia te
s BIO-137
first
BIO-136
used in n
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Carbon dhoNide BIOLOGY
Nmolecules re reduced
tvWO
oxidizal, releasing o
NADII
eries of
steps. citrate is prcess, three NADt (clependinu 9What are the Products of the Citric Acid Cycle?
the or (ilP
fed into the sycle. In
nd one Al pro. e Answer: [MODEL QUESTION

TI
SrOup F:ADI:, final roduct
ndured to Because he A arbon
OnetAd molarule is substr.ate-level phosplhory lation). continuQusty in the presence ofth cal atoms come into the citric acid cycle from
pe) Is produrnd
iby
reaetnt, tlhe eycle runs
nr Car out of the six carbons ot one glucose molecule. Twoeach acetyl group, representig
carbon dioxide molecules are
is also the tirst
cdi
Cric cyele ased on each turn of the cycle; however, these do
not necessarily contain the most
suflicient eactants. recently-added carbon atoms. The two acetyl carbon
atoms will eventually be released on
Steps in the Citrie Acid Cycle step. combining
thg-(Wo-carbon acetv
is a condensation later turns of the cycle, thus, all six carbon atoms from the original glucose molecule are
form a siv0p

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Step : The tirst step four-carbon oxaloacetate molecle to eventually incorporated into carbon dioxide. Each turm of the cycle forms three NADH
(trom acetyl CoA) with a sulfhydryl.group (-SH) and diffuses 0 molecules and one FADH2 molecule. These carriers will connect with the last portion of
molecule of citrate. CoA is bound.to a
l inaith another acetyl group. This step s ireveIe Decause it i aerobic respiration to produceATP molecules. One GTP or ATP is also made in each
nighty esergonic The rate of this reáction is controlled by negave feedback and
levels.increase; the rate of this reaction' decrease
ses.
tyele. Several of the inemediate compounds in the citrie acid cyele can be used in
synthesizing non-essential amino acids; therefore, the cycle is amphibolic (both catabolic
amount of ATP available. If ATP
ATP is in short supply. tke rate increases. and anabolic).
as Ciurate is.converted into Breakdown of Pyruvate
Step2: Citrate luses one water molecule and gains another
After glycolysis, pyruvate is converted into acety! CoA in order to enter the citric acid
ISOmer. iSOLUrate.
a. cycle.
Steps and 4: In step three. isocitrate is oxidized, producing a five-carbon moleule.
AK
ketogiutarate. together with a molecule of CO; and two clectronis, which reduce NAD+1 [MODEL QUESTION]
hua 23. Define Photosynthesis.
NADH. his step is also regulated by negative feedback from ATP and NADH and
FOsitive efect of ADP. Steps three and four are both oxidaion and dearboxylation steps,
Answer:
Photosynthesis is' a process used by plants in which energy from sunlight is used to
which release electrons that reduce NAD to NADH ánd, release carboxyl groups tha
form CO: molecules. a-Ketoglutarate is the product of step
convert carbon dioxide and water into molecules needed for growth. These molecules
ud
the product of step four. CoA binds the. succinyl grup to form succinyl CoA. The
usuceny group 1s include sugars, enzymes and chlorophyll. Light energy is absorbed by the green chemical
enzyme hat catalyzes step four is regulated by feedback inhibition of ATP, succinyl chlorophyll."
COA, and NADH. All animals and human beings are dependent on plants for food and thee plants
is
synthesize the food via physio- chemical process called Photosynthesis. This process
M

Step 5: A phosphatë group is substituted for. coenzyme A,

and a high- ènergy bond 1s important because:
fomed. This energy is used in substrate-level phosphorylation
(during the convérsion o source of food.
the succinyl group to succinate) to form either
guaniné triphosphate (GTP) or ATP. There t.is the primary atmosphere.
are two forms of the enzyme, called isoenzymes, :It results in the release of Oxygen in
for this step, depending upon the type o
animal tissue in which they are found. One [MODEL QUESTION]
amounts of ATP, such as heart and skeletal
form is found in tissues that .use, larg 24. Where Photosynthesis does takes place?
muscle. This form produces ATP.
form of the enzyme is found in tissues The seco Answer: in chloroplast,
such as liver. This form produces GTP.
that have a high number of
anabolic. pathwayo Photosynthesis includes series of chemical reactions which are carried out
In these series of reaction, water
i.e. The specialized structures found on cells of plants.
E

GTP is energetically.equiválent to:

its use is more restricted. In particular, ATP; hoWEy in this reaction energy from sunlight is
Step 6: Step six is a dehydration profin synthesis primarily uses GTP. and carbon dioxide áre converted into glucose and process requires input of energy.
hydrogen atoms are transferred to
process that converts
succinate into fumarate Two. used. Because, it is an endothermic reaction, the entire
as it includes loss of
Photosyinthesis is also classified as oxidation reduction reaction
-
FAD,
electrons of these atoms is insufticient producing FADH2. The energy containc dioxide.
Unlike NADH. this carrier remains to reduce NAD' but adequate to reau FAD
D
electrons by water and gain of electrons by carbon
in Mesophyll Cells and the carbon dioxide
AR

attached to the enzyme rons to The process of photosynthesis takes place

the electron transport chain and transfers the ele stomata, i.e. the small holes present on the
directly. This process
is made possible by the localiza o required by the process enters the process via
the enzym: catalyzing this process is transported via roots through
stepinside outer layer of leaves. The water required for the
Step 7: Water is added to,fumarate the inner membrane of the mitochondrion.
during step seven, last the vascular tissues.
in image below) consisting of the
step in the citric acid
cycie regenerates oxaloacetateand malate is produceu other he chloroplast contains membranous system (shown
light energy
molecule of NADH is produced. by oxidizing malate stroma lamellae, grana and the fluid stroma. The membrane system traps the

BIO-139
BIO-138
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PUBLICATIONSS eagram slhovws th deeton
N:ADPH.
Folowing
and Answer:
synthesizing ATP

TI
In Calvin Cycle, Carbon atoms irom CO2are fixed
in and are used to form three - Carbon
nd helps of'a sortion of chloroptast: Puter menmbrane Sugar. This process IS dependent on ATP and NADPH formed from light reactions.
croraph light reaction is .carried out in thylakoid membrane while the Calvin Cycle
The
Inner membrane takes place in
stroma. The Calvin cycle can be described in three stages:
- Stromal lamela
Carboxylation- It is the fixation of CO% in stable organic intermediate. It is an

AU
- Grana.
important stage in Calvin Cycle where CO is utilized for carboxylation
of RuBP in the presence of enzyme RuBP carboxylase. It results, in the formation
of 2 molecules of 3-PGA. RuBP carboxylase also helps in oxygenation activity
Stroma and is therefore also referred as RuBP carboxylase oxygenase (RuBisCO).
Ribosomes Reduction This stage includes series of reactions that result in the formation of
-

glucose. This step utilizes 2 molecules of ATP (for phosphorylation) and two
Starch granue molecules of NADPH (for reduction per COmolecule). The fixation of 6
molecules of CO2 and 6 turns of cycle result in the removal of molecule of 1

-Lipid droplet
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glucose from pathway.
Regeneration- This stage includes. regeneration of CO2 acceptor molecule and
25. What are the Types of Photosynthetic Reactions? [MODELQUESTION requires I
ATP for phosphorylation to form RuBP.
Answer: Following diagram represents the entire Calvin cycl, as discussed above in detail. The
Photesynthetic Reactions are of two types, i.e. cycle starts with carboxylation, followed by reduction and then, finally regeneration. The
Light Dependent Reaction In these reactions, the energy from sunlight s
-
last stage includes regeneration of CO2 acceptor. molecule and requires 1 ATP for
absorbed by chlorophyll and transformed into chemical.energy. in the form phosphorylation to form RuBP:
of ATP and NADPH (electron carrier moleculè).
3CO%
Light Independent Reaction This reaction is also referred as Calvin Cyele. Ia
Carbon
M

fixation
this reaction. the energized electron from light dependent reactions provides RuBisco
energy to tom carbohydrates from CO% molecules. 3RuBP

26. Define Biosynthetic Phase.

IMODEL QUESTION)
Answer:
Biosyrithetic Phase is the process by
3 ATP)
o00 '6 3-PGA
which carbon dioxide ADP)
and the process is termed as carbon is reduced to carbohydra
fixation; it makes use of the
produced in the light phase. This ATP and NA
E

process occurs in the 6AD

help of series of enzyme-catalysed reactions. stroma of chloroplasts wiu the Regeneration

27. How ATP and NADPH

6NADPH L Reduction
are used in Biosynthetic 6 NADP*}
Answer: Phase?[MODEL QUES N G3P are recycled
AR

We are aware of the fact

that CO2 1s combined wer
very eager to find out with H;0to produce
how this reaction proceeded sugar. Scie t the GOes to make.glucose
use of radioisotope and just after
I4Cled to Second Worla
Carbon Organic Acid. Melvin the discovery that the first CO2
fixation produ
was 2What are the reactions involved in Calvin Cycle?. [MODEL QUESTION]
compiete biosynthetiC patnwayCalvin contributed in answering the Answer:
1s named as
was PGA. i.e. 3-Phosphoglyeric Acid. Calvin Cycle. this and thercdud Reactions in Calvin Cycle
The identifica
first wth reference to the above diagram, the reactions are divided in three different stages:
P
28. Describe the Calvin Cycle. Carbon' Fixation'"- A CO: molecule combines with 5 C acceptor molecule ànd
RuBP. This step makes 6 Carbon compound that, splits. into 2 molecules of 3
IMODELQUESTioN
BIO-140
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BIO-141
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neaction is catalyzed by RuBp. rboxylase Atmospheric CO;
3PG:A. The o
Carbon compound and
Mesophyl
NADPH are convert cd

TI
ONYgenase to 3 PGA Plasina
second stage. ATP and cell membrane
Reduction - At the and G3P lyceraldelhyde-j
molarules of a three carbon Sugar
molevules into Cell wal
phosphate). make glucose whi.
3GP molecules go to HCO0 Phosphoenol
Regeneration - At the tinal stage. regene
regenerate RuBP acceptor. The process of
PYTuvate
eneration
may be exycled to

AU
ATP along with complex network of reactions.
quires
For exiting cycle. thee COmolecules enter the
cycle for exiting 3GP molecule .
Fixation
hi Kegeneration
provides three new atoms of tixed carbon. Entering .of 3CO2molecules, resule sults
regeneration of molecules of RuBP acceptor. C4 acid C3 acid

Plasmo-
30. Describe The Ca Pathway. [MODELQUESTION desma

Answer: Bundle
Plants that camy out Ce pathways comprise of specitic enzyme that are located in two shea
AK
ditferent cell types. i.e. Mesophyll Cells and Bundle Sheath Cells. This pathway is the
-

method that is used by plants to convert atmospheric

carbon dioxide in chemical Transport Transport
compound containing four carbons. This pathway is
used by the plants in subtropical
areas such as Sugar Cane, Maize, Millet, Papyrus Fixation by
and Sorghum. These plants are special
and have several type of leaf anatomy, i.e. Calvin cycl
they can tolerate higher temperature and aso
show response to high light intensity.
This pathway is cyclic in' nature. The
PEP (phosphoenol pyruvate) and
primary CO2 acceptor
is. 3-Carbon Molecule
coDecarboxylation
..

is present in mesophyll cells.

carboxy lase is the enzyme
that is responsible for this PEPcase or r
M

the mesophyll cells do fixation. It is important to note

not have RuBisCO enzyme
cells. and C acid OAA is formea
After this. 4- carbon compounds
cells which are then
like aspartic. acid
or malic acid are formed mes phyl 31. Define Photorespiration. [MODEL QUESTION)
transported to bundle
sheath cells, where C4 in Answer:
releaseCarbon Dioxide (CO:) acids are down lo Photorespiratión is a biochemical process in plants in iwhich, especially under conditijons
transported back and three carbon molecules. brokens water stress, oxygen inhibits the Calvin cycle. the carbon fixation portion
to mesophyll cells where
the cycle. The CO2 released it gets converted
These 3 Carbon m0Eefine of of
These bundle sheath enters in bundle in PEP, thereby C wa photosynthesis.
E

sheath Photorespiration. results in light dependent uptake of Or and, release CO: and is
(RibuloseBiphosphate cells have surplus cells and thereby the Calv of
Carboxylase - Oxygenase) and
of an enzyme callea isCO
RuBi associated' with metabolism and synthesis .of small molecule named glycolate. This
diagram explais
the entire Ca pathway is deficient PEPcase. Followne
aeficient in PEPcase simultaneously takes place in green plants along with phofosynthesis. Its end
Processdecreases
as discussed
above: result the net amount of CO: and both photosynthesis and. photorespiration
AR

Vorks opposjte to each other.

32. What happens in the energy payoff phase of glycolysis?, [MODEL QUESTION]
Answer:
additiona stéps and results in the.
The energy payoff phase of glycolysis consists ot ivepyruvate
tormation of.four ATP. two NADH H and two mólecules. Substrate level
phosphorylation is the process by whicn Al iS produced trom the transfer of a
phosphate group from a substrate molecuje in a metabolic pathway..
BIO-143

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What are the

influencing factors
of
Photoynthesis?
MODEL QUESTIONI
.34.What are the.Energy-yielding and energy-consuming reactions?
BIOLOGY

TI
S.
Answer [MODEL QUESTION]
Photusyntdesis photosynlnesis,. I
hese factors are both Answer:.
Factors affectiig
fiartors that attit
ths ale o The work of biological growth depends on the. transfer
here are several tactvrs: tactors are no limitin
of energy from catabolic
(yielding) to anabolic. (consumhg) reactions, Classically, the two reactions
ntertnal ad eteriai and other ng
cardn dianide. light temperature. The mos have .been
depicted to be connected by ATP, in the sense that the energy'released by, for example,
.Teaper:urr W'heninsrases
-

with the rise n

results, in inactiva the glycolytic breakdown of sugars is conserved in,the form of ATP, which then provides

AU
pretsy nthesis rate High temperature
ange of temperature is &C-3*C. enzy mnatically controlled dark reactions. the enérgy. necessary for the biosynthesis of cell material.; It is now clear that most
enzyms and thereby starts limiting fäctor 'and its organisms, including anaerobes, can conserve.energy, in the form of a transmembrane
Conventration- lt is themajor., electrochemical gradrent'of protons, or protonmotive force. However, the protonmotive
Carcon Dionide :0.04%. Increase in
atnmosphre. i.e. 0.03
conentrativn is ver low in force drives few biosynthetic processes directly, 'and the trànsfer of energý from the
increás in fixation rate of CO. Added to this. the
concentration to 0.05*3 causes protónmotiye force. to ATP via a membrane-bound reversible: ATPase is a vital link
concentration of carbon dioxide. "The
C: and Ca piatts diferentty respond to the between catabolic.änd anabolic reactions.
fact that C: piants raspond to higher CO; concentration by showing-increased rate
of pketosyatasis leading to higher: productivity. has beenused forsome 35. What are energy yields? [MODEL QUESTION]
AK
greerkouse craps ike bel pepper and tomatoes.Such plants are allowed Answer: energy.
to

grow in C0: 2nriched environment that leads ta higher yields. net

The energy yield refers to. the amount of energy that.is gained from harvesting
3. Light -The ighi varies as per quality, diration and intensity and has significant an source; This yield is the.: total amount of energy gaiñed from harvesting the
umpact en te rate oi photosynthesis. For instance, there is a linear relationship. Source after deducting the amount of energy that was spent.to harvest it.
berween iacident ight and CO fixation at low-light irntensities. Added to this,
36. What is the relationship between free energy and metabolism?
increase in. eincident light beyond point causes breakdown chlorophyll and
of IMODEL QUESTION]
decrease in photosynthesis: Answer:
Oxygen O:gen inhibits photesynthesis in Ci plants but Ca plants show lite Free energy is energy that is availablë to do' cellular work
M

effect. This is so because Caplants carry'out photorespiration and high oxygen

Entropy (S), and free energy (G) are relatd inversely. G=H-TS, where G=free
stimutates it The rate of photosynthesis increases. energy, H = enthalpý of the system, T is the absolute temperature expressed in degrees
with, the, reduction
concentretion of oxygen.
Kelvin, and S js entropy. Free energy. decreases during an exergonie reaction.
Water lt is an essentia raw material
for the assimilation of carbon. Le2 than
one percent of absorbed water is utilized
in photosynthesis. 7 What is metabolic energy?
37. [MODEL QUESTION]
water content in soil decreases the The decrea
ate of photošynthesis as well. T

nisal Answer: from nutrients. Metabolism

because it results in dehydration
of protoplasm and also results Energy metabolism is.the process of generating energy (ATP)
çan function in the presence or
in state
E

closure. Added to this, ít impairs

enzymatic efficiency, lo omprises a series of interconnected, pathways that
inhibits respiration, etc. "ac eiiciency, affects its colloidal coo converts one glucose molecule into 30-32 ATP
abserice of oxygen. Aerobic metabolism
6. Mineral
elemenS-These are also essential molecules.
includes Cu. Ci. Mg. Fe, P fo. the growth of plants and ofit
and these are closely
photosynthesis. related with the proSS
S8. What type of energy are high net energy yield? [MODEL QUESTIONI
AR

7. Air.poliutants Answer:
Metallicand gaseous polutants energy available from a resource after the
pollutants include SO2,
oxidants, ozoneand reduce photosyntne. Net energy is the amount of high-quality usable

.
is subtraced.
8. Chemical compounds- hydrogen fluorides. amoünt of energy neded to make it available
quantity but even the
Although, chemical.compounds
arc present
es [MODEL QUESTION]
the rate of photosyi"es, How energy is extracted from glucose?.
smali quantity depresses On
contrary, increase in thè presence
Thus, there are several factors of chemical
compound results in dy f cel5 la
that affect the rate clude
inclu
content ofchlorophyi. proxopiasmiç of photosynthesis.
factor, accumulation Other faclo
of carbohydrates,
et. BIO-145

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converted nto energy
energy in loOd is
Answer: eellular
respiratin, the
respiration. glucose. and au are charge. In addition to direct
BIOLOGY
nrough the processthe of During cellular
to ATp *S€n

TI
regulation
by body's cells. energy is trans ferred AMP-activated protein of several enzymes by adenyl
at can be used waten and the kinase known as nucleotides, an
Converted into carbon
dionide and key enzymes when the energy charge AMP-K phosphorylates and thereby regulates
decreases. This
during the energy yielding. Dha.
pase pathways while swilching on catabolic results in switching
of anabolic
ofenergy are released of
[MODELQUESTIONI pathways when AMP
40. What forms Life depends on an adequate energy charge. ATP increases.
glycolysis? to maintain an adequate energy If synthesis is momentarily insufticient
r
.
charge, AMP can be converted

AU
Answer: pyruvate. molecules: Glycolysis, to hypOxanthine and ribose-5P, followed by two different pathways
2 NADH. and 2 by irreversible oxidation
Glyeolysis produces 2 ATP. energy in the form of ATP
NA acid. This helps to buffer the of hypoxanthine to uric
glucose, produces adenylate energy
aerobie catabolie breakdown of to produce more energy. {ATP+ADP+AMP} concentration. charge by decreasing the total
and py ruvate. which itself enters
the citric acid cycle

in biological system?
41. What do you understand by energy charge [MODEL QUESTION]
Answer: .
energy staus of biological cells.
Ihe eneryY charge is an index used to measure the
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ATP or ig-ATP is the principal molecule for storing and transferring energý in the cell:
it is used for biosynthetic pathways, maintenance of trans-membrane gradients,
movement. cell division. etc. More than 90% of the ATP is pfoduced by phosphorylation
of ADP by. the ATP synthase. ATP can also be produced by "substrate level
phosphorylation" reactions (ADP phosphorylation by (1, 3)-bisphosphoglycerate,
phosphoenolpyruvate, phosphocreatine), by. the succinate-CoA igas and
phosphoenolpyruvatecarboxylkinase. and by adenylate kinase, an enzyme, that maintains
the three adenine nucleotides in equilibrium (ATP + AMP
2ADP).
M

The energY charge is related to ATP, ADP and AMP concentrations. was
It first detineu
by Atkinson and Walton who found
that it was necessary to
concentration of all three nucleotides, rather than just take into account u
ATP and ADP, to account 1or ie
energy status in metabolism. Since the adenylate
kinase maintains two ADP Imolecu
equilibrium with one ATP (2ADP ATP+AMP ), Atkinson defined the adenyia
energy charge as:

ATP)+[4DP]
E

Energy Charge =
[ATP]+{AMP]+[ADP|{ATP}
The energy charge of most cells varies
between 0.7 and 0.95-oscillations
quite frequent. Daniel Atkinson showed in this raua6
that when the energy charge
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to 1.0. the citrate lyase and phosphoribosyl increases enzymee

controlling anabolic (ATP-demánding) pyrophosphate
pathways synthetase,' two the
phosphofructokinase are activated, whilenirolling
and
amphiboiic pathways (supplying he pyruvate dehydrogenase,
two enzymes
ATP as coiale
are inhibited. He concluded that control ofwell importarit biosynthetic
as
energy charge within rather narrow these pathways
has evolved to ma
interin he
limits in other
-
words, that
ik
the pi of a cell, must be bueredat energy chargnabolic
all times. We now know that the
and catabolic pathways are Haeed
controled, directly and most if not
indirectly, by tne
an energ
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Answer: (d)

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3.. An outbreak of sepsis
newborn nursery. You caused by Staphylococcus
are aureus has occurred in
Chapter at a Glance. of the normal flora, what iscalled upon to investigate. According to your the
being unicellular (single the most likely source of knowledge
those the organism?
study ot mierewrganisnis MCrOb{OlORY Cncompasses numero erous a) Nose
Microbiology is the (lacking vells). b) Colon [MODEL QUESTION]
wlony). or aceliular c) Hand
E.ulticellular (vell vinelogy. parasitologs. my vlogy ang bactertology Answer: (d)

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d) Throat
ubdisciplines including membrane-bound cell organelles and
possess
Eukaryotic mierrgamsms or wnicn are mcroorganisms-are 4. Each of the following
wheneas prkary otic onganisms-al organisms is an important
neiude fungt and protists. membrane-bound organelles and except: cause of urinary tract infections
conventivnally classtied acking
traditionally relied on Culture, staining, and a) Klebsiellapneumoniae [MODEL QUESTIONI
incfude Bateria and Arhaea. AMienvdbiologists b) Escherichia coli
common environments can c) Bacteriodesfragilis
micruscop. However. less than
1
of the mienoorganisms present in d) Proteus mirabilis
e cuitured in isolation using current means. Microbiologists often rely molecular biology tools
on Answer: (d)
TRNA gene seqyuence used for
such as DNA sequenc basad idenification. tor example 16s
bacteria identitication. 5. A 30 year old woman has non-bloody diarrhea
of the following organisms is for the past 14
Viruses have been variably classified as organisms, as they have been considered either as very
least likely to cause this illness? hours. Which one
AK
simple microorganisms or ver complex molecules. Prions, neyer considered as microorganisms,
have been investigatei by virelogists, however, as the clinical effects -traced to them were a) Streptococcus pyogens [MODEL QUESTION].
b) Clostridium difficile
originally presumed due to chronic viral infections, and virologists took
search-discovering c) Shigelladysenteriae d) Salmonella enteritidis
"infectious preteins Answer: (d)
The existence of micreorganisms was predicted many centuries
before they were first observed,
tor example by the Jars in [ndía and by Marcus 6. Each of
Terentius Varro in ancient Rome. The first the following agents is a recognized cause of
recorded microscope observation was of the fruiting bodies diarrhea except
of moulds, by Robert Hooke in 1666,
but the Jesuit priest Athanasius Kircher
was Ilikely the first to see microbes, a) Clostridium perfringens [MODEL QUESTION]
observing in milk and putrid material in 1658. which he mentioned b) Vibrio cholera
Antonie van Leeuwenhoek is c) Enterococcus faecalis
considered a father of
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microbiology as he observed and d) Escherichia coli

simple microscopes of his own
experimented with microscopic
organisms in 1676, using Answer: (d)
design. Scientfic microbiology developed
through the work of Louis Pasteur in the.19th century
and in medical microbiology Robért 7. Each of. the following statements
Koch. about the classification
correct except of streptococci is
Multiple Choice Type Questions. a) Pneumococci (Streptococcus [MODEL QUSTION
: serotyped on the. basis of their pneumoniae) are alpha-hemolytic and can be
1. The identification of bacteria polysaccharide capsule
by.serologic tests is based b) Enterococci are group D streptococci
specific antigens. Which of on the presence o and can be classified by their ability
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the following bacterial grow 6.5% sodium chloride to.

contain useful antigens? components is least likely c) Viridans streptococci are identified by
a) Capsule Lancefield grouping, which is
[MODELQUESTIONI
b) Cell wal on the based
c) Flagella Ccarbohydrate in the cell wall
Answer: (d) d) Ribosomes d) Although pneumococci and the
viridans streptococci are alpha-hemolytic,
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they can be differentiated by the bile

2. Each of the following solubility test and their susceptibility
statements to optochin
concerning the Gram Answer: (d)
stain is correct excep
a) Escherichia coli stains
b) Streptococcus pyogens
pink because it has a [MODEL QUESTIONJ 8. Which of the, following bacteria has
ayer stains blue becausethin peptidoglycan layer the lowest,50% infective
dose (ID50)?
it has a thick peptidoglyca
c) Mycoplasma pneumoniae :
a) Campylobacter jejuni, [MODEL QUESTION]
is not visible in
the Gram's b) Salmonella typhi
not have a cell wall C) Vibrio cholera "
d) Shigellasonnei
7

d) Mycobacterium stain because it do

tuberculosis stains blue
because it has
a thick lipid layer BIO-149
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Answer: (d) Some living organisms are
by serologic means?
unicellular which means that
This means that, this single, they only consist of one celi.
9. Which of the following
disease is best diagnosed [MODEL QUESTION cell will be able to
living organism. Euglena has chloroplasts show all the characteristics
b) Gonorrhea
.

features include flagellum (for movement), which is typical of a plant. Typical

of a.
a) Pulmonary tuberculosis lack of cell wall.
animal
d) Q Fever
c) Actinomycosis
Answer: (d 6. Which single celled organism has Pseudopodia?

AUÅnswer:: MODEL QUESTIONJ

[MODEL QUESTIONJ
10. The cogulase test is used to differentiate An amoeba, sometimes written as "ameba",
is a term generally used to describe
a) staphylococcus epidermidis from Neisseria meningitides celled eukaryotic organism that has no definate a single
shape and, that move by means
Staphyiococcus aureus from Staphylococcus epidermidis of pseudopodia. Pseudopodia or pseudopods are temporary
"

c) Streptococcus pyogens from Staphylococcus aureus the word literally means "false feet" projections of the cell and
d) Streptococcus pyogens from Enterococcus faecalis
Answer: (d) 7. What are the similarities and differences
organism? between unicellular and multi cellular
& Long Answer Type Questions [MODEL QUESTION
Short Answer:
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Similarities:
1. What is in a single celled organism?
Answer;
[MODEL QUESTION] One important distinction hereis whether we're. talking about
prokaryotes,i.e.
organisms without a complex cell structure, and/or eukaryotes,
A unicellular organism. also known as a single-celled organism,,is an organism thar nuclei and other structures. This would significantly affect organisms that have
consists of only one cell, unlike a multicellular organism the comparison.
cell
that consists of more than one However, generally speaking, we can say that unicellular and multicellulár organisms
:are alike in that they exhibit all the functions
of life, such as a metabölism and
reproduction, they contain DNA and RNA, they cani
exhibit a
and they are essential to almost every ecosystem that we currentlywid
2. What was the first single celled organism? range of lifestyles,
[MODEL QUESTIONJ know of.
Answer:
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The first living thing on Earth, single-celled

a cell nucleus or cell membrane known as
micro-organisms or microbes
1ac5 Diferences:
prokaryotes, seem to have Unicellular organisms can reproduce faster and in greater
Earth almost four bilion yeàrs ago, just first appeareu numbers. are
of the Earth itself.
a few huindred million years
after the formauo
also capable of actually sharing DNA, between living individuals, whichSome ofthem
is impossible for
more complex life withoit technological intervention.
3. What are 3 examples of unicellular
Multicellularrorg are almos lways larger.
organisms? [MODEL QUESTIONJ Unicellular organišms are more commonly found. in extreme environments;
Answer: the
Examples of unicellular organisms:
archaea, the third domain of life; counts among its members a number of "extremophiles"
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Bacteria (E.coli, Nitrospirae,Sireptobacilliu. Single-celled organisms that thrive in environiments or exireme heat, cidity, salinity,
etc.
(photosynthetic algae), BrewerS 'itlomycetes, etc) Diatoms
Yeast, Amoeba, .°. Multicellular organisms typically experience severe stress or.death if a certain
Slime molds, etc. A unícellular organism 15 l'ai.ecium, Euglena, Phytoplan on,
one where a number of cells die or are separated trom tne group; unicellular organisms have no
has a complete set of its species DNA. single cell is the individual ana
. comparable problem.
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Multicellular organisms require more 1ood ana iiving space and typically occupy a
4. What is the largest single celled organism? higher link in the food web.
Answer: Biologists used the wOrid's [MODEL QUESTION a
largest single-celled organism,
called Caulerpa taxifolia, to study the nature Multicellular organisms may be better equipped to survive harmful DNA mutation
of structure and form an aquatic due to redundancy in other clls, but thney, are aisO at risk ot cancer and. other
related
cell that can grow toa length of six to twelve inches. in plants,
plants. It is asin uses tliat have no comparison in the unicenular organism.
5. What are characteristics of unicellular organisms7
MODEL QUESTION BIO-151
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species concopt. Running a Fever

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8.What is the bacterial concept posits tUan a Dactcrial
specics i Fluid Drainage*
Answer: bacterial species organinms that show a
einerging phylo-phenetic Continual or Increased Pain
nc genomically coherent cluster of
indivIdUal
cmracleristics, and isS Redness and Swelling.
**
*

a monophyletic and similarity with respect to many imdependent

high deyree of overall Hot Incision' Site.
phenutypie prpeny
diagnosable by a discriminative
.

9. What is strain?
Answer:,
A strain
a virus or
the
*is
agenetic variant or. subtype of
bacterium
intluenza or
or
"tdu"
fungus.
virus.
For example:
Properly
have species. because they do not have
speaking
[MODEL QUESTION
'

amicroorganiSm, that. Is to say..

a "tu strain" Is a certan biological
form of
Bacteria, Archaea and viruses do not
eukaryote-type sexual reproduction. Baçteria do
exchange DNA, but they may exchange it between different kind of bacteria, illustrating
their considerable ditference from eukaryotes. Strains are herefore an. absolutely.
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14. Describe the sSification
Teatures.
Answer:
.
classification of

Microorganisins or microbes are microscopic.

Microorganisms?. Give their :identification

multicellular, or cell clusters. Microorganims are widespread

to lifë, but isome can.cause .serious harm. They can be divided
bacteria, archaea,.fungi, protozoa, algae, and viruses.

Bacteria
*
[MODEL QUESTION]

organisms that .exist as unicellular,

in.nature.and are beneficial.
into ix major types

.
.

'.
AK
essential art of bacterial identitication. Bacteria are unicellular organisms. The cells are described as prokáryotic
because they
lack a nucleus. They exist in four major shapes: bacillus (rad shape), cöccus
10. What is type strain?. IMODEL QUESTION) (spherical
shape), spirilla. (spiral shape), and vibrio (curved "shape). Most baçteria have: a
Answer:
peptidoglycan cell wall; they divide by binary: fission; and they may possess flagella.for
Type strain is the strain, which was used when the species was described for the first
motility. The difference in their cell wall structure is a major feature used
time and which was selected by the author as the type strain. A strain designation in classifying
including superscript T(e.g. B78') šhows the the strain is a type strain. . these organisms.
According to the way:their cell. wall structure stains, bacteria çan be classified as either
11. What do you mean by strain of bacteria? Gram-positive or Gram-negative when using the Gram staining. Bacteria can be further
. [MODEL QUESTION]
,divided based on their 'response. to gaseous oxygen into the following groups: aerobic.
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Answer: *
In microbiology or virology, a strain is å genetic variañt or . (living in the presence .of oxygen), anaerobic (living without oxygen), and facultative
subtype of a micro-organism anaerobes (can liv in both environments).
(eg, virus or bacterium or fungus). For example;. Escherichia
studied bacterium and encompasss coli a wel
i According to the way they obtain energy, bacteria are classified as heterotrophs or
àn enormous population of bacteria that exhibIt a. autolrophs. Autotrophs make their own food by using the energy of sunlight or chemical
very high degree of both genetic and phenotypic
diversity. reactions. in which case they are called chemoautotrophs. Heterotrophs obtairi their
12. How many energy by consuning other organisms. Bacteria that use decaying life forms a a source
E coli strains are there? [MODEL QUESTIONJ
Answer: of energy are càlled'saprophytes.
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Microbiologics offers over 45 different

strains of E. coli including O157:H7, 0104:1
and the Big 6 Shiga toxin-producing strains. Archaea.
format for your lab.
Visit our website to find the right
strain a Archaea or Archaebacteria differ from tirue bacteria in their cell wall. structure and lack
peptidoglycans. They are prokaryotic cells with avidity to extremè environiental
13. What are the four types of infection? conditions. Based on their habitat, al Archaeans can be divided, into. the following
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[MODEL QUESTION] groups: methanogens (methaneproducing organisms). halophites (archaeans that ive in
Answer: Salty environiments), thermophiles (archaeans that live at extremely hot temperatures),
Types of infection include bacteria, fungal; viral,
protozoan, parasitic, and prion diSe and psychrophiles (cold-temperature Archaeans). Archaeans, use different energý sources
What are the five signs of an infection!. ike hydrogen gas, carbon dioXIde, and sulphur, Some of them .use sunlight to make
if you notice any of the following signs, see.your. energy, ,but not the same way plants do.hey absorb, sunlight using their. membirane
doctor as soon as possibie lor
infected wound treatment. pigment, bacteriorhodopsin. This reacts with lignt, leading to the formation of the energy
Feelings of Malaise. Malaise, is a common non-specific
sign of a localized systent molecule adenosine triphosphate (ATP). .
.
infection.
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microscopy: optical, clectron, and
nucleus). Mos scanning probe microscopy,
cells (Wn a lruc field of X-ray microscopy. along with the emerging
ane eukaryolic nutriente

TI
Fungi
(mushnaom, molds, and
yeasts)
chitn. Ihey obtain ts by
Fungi is composed of
are multicellular and
their cell wall
environiment (decomposers); hrough symbio 16. What is Optical microscopy?
fungi from their (parasileel Answer: [MODEL QUESTION]
absorbing organic
material relationships with a host
(symbionts). or hamful Optical or light microscopy involves
relationships with plants absorD 1material,Th
filamentous tubes called hyphae-that help from the sample through a single lens
passing visible light transmitted through
or reflected
They formi characteristic by releasrng spores. or multiple lenses to allow a magnified view
myrelium. Fungi reproduce sample. The resulting. image can be of the
collection ot hyphàe is called

AU
detected directly by the eye, imaged
a photographic plate, or captured digitally. on
The single lens with its attachments,
system of lenses and imaging equipment, or the
Protozoa
eukaryotes. They have a nucleus, Complex organelles along with the appropriate lighting equipment,
Protoza are unicellular aerobic structures. They sample stage, and Support, makes up the basic
absorption or ingestion through specialized light microscope. The most recent
and obtain nourishment by terms df numbers, biomass, and
development is the digital microscope, which uses
grvup of organisms in the vWorld
in a CCD camera to focus on the exhibit
make up the largest of interest. The image is shown on a computer screen,
diversity. Their cell walls are made up of cellulose.
Protozoa have.been traditionally so eye-pieces are unnecessary.
divided based on their mode of locomotion: flagellates produce their
own food and use
17. What is Electron microscopy?
their whip-like structure to propel forward, ciliates have tiny hair .that beat to produce [MODEL QUESTION]
Answer:
movement. amoeboids have false feet or pseudopodia used for feeding and locomotion, Until the invention of sub-diffraction microscopy,
AK
the wavelength of the light limited the
and sporozoans are non-motile. They also have different means of nutrition, which resolution of traditional microscopy to around
groups them as autotrophs or heterotrophs.
0.2 micrometers. In order to gain higher
resolution, the use of an electron beam with a far smaller
wavelength is used in electron
**.
microscopes.
Algae Transmission electron microscopy (TEM) is quite similar
Agae, also called cyanobacteria or blue-green algae, are unicellülar to the compound light
or
multicellular microscope, by sending an electron beam through a very
thin slice of the specimen.
eukaryotes that obtain nourishment by photosynthesis. They live in water, damp O1l, ana
The resolution limit in 2005 was around 0.05
rocks and produce oxygen and carbohydrates used by other organisms: nanometer and has not increased
cyanobacteria are the orngins of green land plants. It is, believed that appreciably since that time..
Scanning electron mieroscopy (SEM) visualizes details on
the surfaces of specimens
M

and gives a very nice 3D view. t gives results much like

Viruses those of the stereo light
Viruses are non-cellular entities that consist.of
microscope. The best resolution for SEM in 2011 was 0.4 nanometer.
a nucleic acid.core (DNA Or RNA) Electron microscopes equipped for X-ray spectroscopy
surounded by a protein coat. Although viruses can provide qualitative and
are classified as microorganisms, they a quantitative elemental analysis. This type of. electron
not considered living organisms.
Viuss cannot reproduce outside host cell and canno microscope, also known as
metabolize on their own. Viruses a analytical electron microscope, can be a very
often infest þrokaryotic and eukaryotic.cells caus powerful characterization tool for
diseases. investigation nanomaterials.
of

. 18. What is Scanning probe microscopy?

E

Multicellular Animal Parasites [MODEL QUESTION]

Answer:
A group of eukaryotic organisms
collectively. refered
consisting of the flatworms
to as the; helminths. Athough they. àrë
definition, since they are
hich
and.roundworms, whic
not microorganisms
This is a sub-diffraction technique. Examples
the atomic force microscope (AFM), the
of scanning probe microscopes are
scanning tunneling microscope, the photonic
large enough to be easily seen force microscope and the recurrence tracking
part of their ife cycle an with the naked.eye, they
physical contact of a solid probe tip to scan the microscope. All such methods use the
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microscopic form. Since the

.
importance, they are oftent parasitic helminths are of
ci
surtace of an object, which is supposed
discussed along with be almost flat. to
the other groups
of microbes.
15. What is Microscopy?
19. What are the different types of Optical
Answer: MODEL QUESTION Microscope? [MODEL QUESTIONJ
Microscopy is, the technical
field of using microscopes
objects that cannot be seen to view objects and arca of
with the naked eye
the resolution range of the (objects that are not,
normal eye) There are three
well-known brancnco BIO-155
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light nicroscope, is. a type Answer:
Answer: n^terred to as the imaoP
microscope, ofen ot lenses to magnify
The optical system
visible light and a
microscope that uses
of
Eyepiece
small subjects. Nosepiece
optical microscopes:
There are tuo hasie types of

AU
1. Siunple mieroscopRS
2. Compound microscopes. Objectives
MODEL QUESTION] Body
20. Describe simple microscope?
Answer: lens for magnification, such' as a
A Simple microscope is one which uses a single
a compound microscope uses several lenses
to enhance
magnitying glass while Specimen stage &
Light
the magnitication of an object. aperture djaphragm
A simple microscope uses a lens to enlarge
an object through, angular
magnificanon alone. giving the viewer an erect enlarged virtual image.
AK
The use of.a single convex lens or groups of. lenses is found in simple
magnificaron devices such as the magnifying glass, loupes, and eyepieces for
telescopes and microscopes. 23. What is Microbial ecology? [MODEL QUESTIONJ
A simpie microscope is actually a convex lens of small focal length, which is Answer:
usad for seeing the magnified images of small objects. Microbial ecology (or environmental microbiology) is the ecology of microorganisms:
their relationship with one another and with their environment. It concerns the three
21. Give the principle of simple microscope. [MODEL QUESTION] major domains of life-Eukaryota, Archaea, and Bacteria-as well as viruses.
Answer: Microorganisms, by their omnipresence, impact the entire biosphere. Microbial life pays
A Simple micrescope works on the principle that when a tiny object is placed within its a primary role in regulating biogeochemical systems in virtualy all of our planet's
M

focus, a vrtual, erect and magnified image of the object is formed environments, including some of the most extreme, from frozen environments and acidic
at the least distance or
distinct vision from the eye held close to the lens. lakes, to hydrothermal vents at the bottom of deepest oceans, and some of the most
familiar, such as the human small intestine. As a consequence of the quantitative
Magnification of Simple Microscope magnitude of microbial life (calculated as 5.0x100 cells; eight orders of magnitude
The magnifying power of a simple microscope is greater than the number of stars in the observable, universe) microbes, by virtue of
= 1 given by:
M D/F their biomass alone, constitute a significant carbon sink. Aside from carbon fixation,
Where, D =least distance of distinct vision microorganisms" key collective metabolic processes (including nitrogen fixation, methane
F= focal length of the convex lens metabolism, and sulfur metabolism) control global biogeochemical cycling. The
E

The focal length of the convex lens should mmensity of microorganisms production is such that, even in the total absence of
be small because smaller the ro al
length of the lens, greater will be ts eukaryotic life, these processes would likely continue unchanged.
magnifying power.
The maximum magnification
of a simple microscope is about 10, which ns
that the object will appear 10
times larger Dy using the mf 24. What is Symbiosis? [MODEL QUESTION]
simple microscope
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maximum magnifcation. Answer:

Microbes, especially bacteria, often engage in symbiotic relationships
22. Drawa simple microscope. (either positive or negative) with other microorganisms or larger organisms. Although
[MODEL QUESTION
physically sImal, symbiotic relationships amongst microbes are significant
in eukaryotic processes and their evolution. The types of symbiotic relationship that
mierobes participate include mutualism, commensalism, parasitism, and ámensalism, and
these relationships affect the ecosystem in many ways.

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microbiial species and bo.

twe
Mutualism ervlogy is a
relationship between
to benetlit. One
siuch ea Answer:
BIOLOGY

uruaiisnm in mierobialhumans that allow tor both sides

TI
spevies and eross-fecding, which IS clearly shown Microbes eXist in all arças,
including homes, offices,
microbial known as snea
as one microbial in-2016, the journal Microbiome commercial centers, and
be sntrophy,. also initially thougt of published hospitals.
Oul Although bryantii, Th microbial ecology of the built environment. a collection of various works studying the
n. triwr: diznsiii.
spevies an S -
orgausnm and JklnCICTerim
needs in orderi
The S
A 2006 study øf pathogenic baçteria in
nis sy sten is
detui!ly two which the bacterium
needs in order to grow hospitals found that their ability
basteriun with the H:. 1or the production of by the type; wilh some surviving for only to survive varied.
organisnn pides the used by the S organism a few days while others survived
The reaxtion The lifespan of microbes for months.
and prduce methane. unfavored) hovvever, vhen coupled to he

AU
in the home varies similarly. Generally
H: Is endergonic (and sv
therm»i nanmically OI methane, the overal require a wet environment with a humidity over bacteria and viruses
kryntii in its production of 10 percent. E. coli can survive
reactivn used by Meirièaterium are a mutualistic relationshin few. hours to a day. Bacteria which form spores for a
in can survive longer, with StaphylococCus
Thus the two organisms aureus surviving potentially for
reaction brones exergonic. environment, deadly ror either species weeks or, in the case of Bacillus anthracis, years.
grow and thrive in an :In the home, pets. can be carriers
which allows them to of bacteria; for example, reptiles are commonly carriers
example of a symbiotic organism.
alone. Lichen is an of salmonella.
S aureus is particularly common, and asymptomatically colonizes
about 30% of the
AmensalSm human population, attempts to decolonize carriers have met with limited success
is a type of symbiotic relationship and
Amensalism (also commonly known as antagonism) generally involve mupirocin nasally and chlorhexidine washing, potentially. along with
unaffected. One example
where one speries oranism is harmed while the other remains vancomycin and cotrimoxazole to address intestinal and urinary tract infections.
AK
is between the microbial
of such a relationship that takes place in microbial ecology
in an
species LucTOU:illus casei and Pseudomonas tactrolens. When co-existing 27. What is Antimicrobials? [MODEL QUESTION
production
environment Ps:uiamonas taetrolens shows inhibited growth and decreased .Answer:
of lactobionic acid (its main product) most likely due to the byproducts created Somemetals, particularly copper and ' silver, have. antimicrobial properties.
by Lactocacilus casei during its production of lactic acid. However, Lactobacillus Using antimicrobial copper-alloý touch surfaces is a technique which has.begun to be
casei shows no difference in its behavior, and such this relationship can be defined as USed in the 21* century to prevent transmission of bacteria. Silver ñanoparticles have also
amensaliSIn. begun to be, incorporated into building surfaces and fabrics, although concerns have been
raised about the potential 'side-effects of the tiny particles on human health.
25. What is Microbial resource management? [MODEL QUESTION)
.
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Answer: 28. What is Sterilization? [MODEL QUESTION]

Biotechnology may be used alongside microbial ecology to address a number ol Answer:
environmental ard economic challenges. For example, molecular techniques such Sterilization refers to any process that eliminates, removes, kills, or deactivates all forms
as community fingerprinting can be used to track changes in microbial communities over of life (in particular referring to microorganisms such
time or assess their biodiversity. Managing the carbon cycle to sequester carbo fungi, bacteria, viruses, spores, unicellular eukaryotic.organisms such as Plasmodium,
dioxide and prevent excess methanogenesis is important in mitigating global warning etc.) and other biological agents like prions present in a specific surface, object or fluid,
and the praspects of bioenergy are being expanded by the development
of microbia u for example food or biological culture media. Sterilization can be achieved through
yarious means,", including heat, chemicals, irradiation, high pressure,. and filtration.
E

cells. Microbial resource management advocates a more progressive

attit Sterilizationm is dístinci from disinfection, sanitization, and pasteurization, in that those
towards disease. whereby biological control agents are favoured over attemp.
eradication. Fluxes in microbial communities has to be better characterized methods reduces, rather than eliminate all foms of life and biological agents present.
potential to be realised. In addition, there are also clinical
for this i After sterilization, an object is referred to as being sterile or aseptic.
implications, as ma
microbial symbioses are a valuable source of existing and
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novel antimicrobial ageni 29. What is growth medium? [MODEL QUESTION]

thus offer another line of inquiry in the evolutionary arms
race of antibiotic resisia Answer:
pressing concerm for researchers. A or
growth. medium culture medium is a solid, liquid or semi-solid designed to
26. How microbes interact with human beings?
[MODEL QUESTION
support, the growth of micrOorganisms or cells or small plants like
the moss Physcomitrella patens. Different types of media are used for growing different
.

types of cells.
.*

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used for,cell culture; wlhich us
uSCspecifie
media are those
growth which
to major types ofplants or animals, and microbiological culture,
he types fo
cel dkrived from fiungi. The most common growth
such as bacteria or o
Swing microvrgnisms, brths and agar plates; specialized media are sometime
microorganisms are utrient organisims, termed fastidis
fasti
for mienwnganism and cell culure growth. Soie
required environments due nutris

S
spcialized due. to. Complex
complex nutritiona
organisms rquire intracellular parasites and rea
equiremenms. Vinuses, fir enample, are obligate

AN
growth medium containine living cells.
MODELQUESTION
30. What are the types of growth medium7
Answer:
The main types.are

TI
.Cultural media
" Minimal media
Selective media
Differential media
Transpoa nmedia
Endicatormedia
AU
31. What is the composition of growth media?
AK
MODEL QUESTION
Answer:
-The most common growth mmedia for miçroorganisms are nutrient
mutrient medium) or LB mèdium (lysogeñy,
bröths :(liquid:
broth). Liquid media are often, mixed wih
agar and poured via a šterile medja,dispenser. into Petri
dishes tà solidify These aga
M

plates provide a solid medium:on which may

microbes be cultured
E
AR
e
W

B10-160