Date EXPERIMENT

20

25 Demonstration through experiment of

breathing out air into limewater that
carbon dioxide is exhaled
during respiration.

o Conicalflasks
MateriaI: O corks
deliveru tube olimewater

Procedure
1. Take twoconical
) Fill y4 volume
flasks as

of cach flask with

shown belowand mark them

limewater.
'A' and B.
3. Close flask 'B'with a cork.

4. Pass a glass tube through anothercork and fix on

it the mouth of flask 'A.
5. Take a deep breath and blow the exhaled air by your mouth in flask "A.

close flaskSs
with cork

Cork

Precautions

1. Cover the mouth of

delivery tube with
flask
your thumb before
blowing so that
lime water atmosphericair does
not enter the flask.
2. Do not suck lime
water into your mouth
Flask A Flask B because it is harmful.
Experimental setup

concerned with this part of respiration that CO,

You have already studied respiratory system and
the released during expiration;this is proved by an
fully understand that oxygen is taken into is

experiment using lime water as indicator for

body during inhalation while carbon dioxide is

or exhalation. The presence of CO, in the exhaled air.

gven out during expiration

It should be remembered that in lungs
supplying energy to the
respiration is essential for
taken in from inhaled air into the blood
Oxygen is

body.
and carbon dioxide is given out of the blood into
During respiratory process
CO, is produced
air. Carbon dioxide turns lime water milky.
so it
and it must be removed to the outside; is

exhaled during expiration. This experiment is

Gaseous Exchange /Experiment 25 11

Homeostasis Experiment 27 17
/
 Observations
Observe the colour change inboth flasks

of lime water.

The lime water in flask 'A'turncd morc

small very
milky immediately and very
'B'
water in flask
change in colour of lime
was observed (verysmallcloudiness).

A Flask B
Flask

concentration
Conclusions The exhaled air contains higher
it that is why lime
water
of carbon dioxide in
in flask A.
turned more milky or cloudy

Viva Voce 25 QRA Short Questions and Answer

Answer the following Questions. which

because of the carbon dioxide
is

Q.1. Theresult youhave noted is only air. Justify.

and not from the surrounding
exhaled by your mouth lime water through
of the exhaled air entered into
Ans. Because the carbon dioxide
it milky. This CO,of
exhaled
the tube and reacted with lime water making
A
mouth into lime water via
air was coming from the lungs through
directly
delivery tube.
carbon
are formed when limewater combines with
Q.2. VWhich compounds
dioxide?
are formed when CO,reacts with lime water.
Ans. Calcium carbonate and water
Ca (OH29)t COa0) CaCO3,t H,O
milky

Q.3. What is the stimulus for breathing in

concentration of carbon dioxide
Ans. The stimulus for breathing is the high
blood.
of any use?
Q.4. Is CO, released during expiration
by green plants.
Ans. very important for photosynthesis
Yes, it is
in large quantity?
Q.5. What is the effect of CO, on breathing if produced
breathing rate along
Ans. C0,produced in large quantity causes an increase in
with deep breaths.
What is the control centre of CO, production and release in body?
Q.6.
located in the Medulla oblongata
of hind brain.
Ans. It is in “breathing centre"

Q.7. How is CO, transported within the human body?

as
Ans. in the form of bicarbonate ions and
It is mainly transported

carboxyhacmoglobin (COattached with haemoglobin).

Notebook 10th (Federal Board)
12 Star Biology Practical
 Date
EXPERIMENT
720

26 Demonstration of the presence of tar in

cigarette smoke and also by charts
showing pictures of lungs
of smokers and non
smokers.

Cigarette without filter stand matchbox

Aoteri funnel whitetissue paper cotton
pictures of lungs of smoker and a non smoker

Procedure Cotton
1. Fix a lighted Precautions
cigarette in a stand
in the 1. Clean the funnel
as shown
properly before
figure. funnel experiment.

Fix a funnel in 2. Do not inhale the

2.
smoke of the cigarette
stand over the because it is injurious
to health.
cigarette and close stand
3. Do not light the
the uppcr end of cigarette through
self

the stem of funnel smoking.

with cotton as
cigarette

showr in the

figure.

Experimental set up to detect tar in cigarette smoke

Observations
by rubbing white tissue paper on the inner surfaceof
Observe thepresence of tar

substance makes the white tissue paper brown.

funnel. Tar which is brown sticky

Observations 2
and observe that tar in the
Examine the pictures of lungs of a smoker and a non-smoker
on the lining of bronchial tubes of a smoker.
Smoke settles
shrunken &
lungs have become blackened,
•Due to deposition of tar the
smokers
fresh looking. &
of non smoker are pink, healthy
unhealthy while the lungs
Gaseous Exchange/ Experiment 26
13

Homeostasis /Experiment 27 17
 those of smokers and note your observations.
lungs with
Compare non-smokers
•
and soot in
blackened due to deposition of tar
The smokers lungs have (may be amph
& alveoli. They have
shrunken duc alveolar damage
bronchioles
lungs are pink, hcalthy
& fresh looking.
The non smokers

Observe the following

do
photographs. What
the
you observe about
position of the hcart in

normal and smoker's

chest cavity?

• The smoker's heart has

enlarged due to over
Non-smoker's lungs
Smoker's lungs
exertion, to pump more
the oxygen requirements of
poorly loaded with oxygen, due
to
blood, which is

the body.

Conclusions 1. Due
chances

2. Walls of

3.
to deposition

cause emphysema.
of lungs

alveoli

Smoking increases the risk

and heart attacks etc..
of tar

are destroyed
inthe lungs
cancer increase.
which may

of tuberculosis
NS
|SMOKING

(substances that
Cigarette smoke contains numerous carcinogens
gases such as carbon monoxide
may cause cancer) and poisonous
and other chemicals. One of these
and hydrogen cyanide
in
tar which is brovwn sticky substance that collects
chemicals is

passes into blood. Tar

is one of the
smoker's lungs from where it

the of wind pipe and lungs.

poisonous chemical that kills cells

Cigarette smoke also contains a strongly addictive drug called

blood can be poisonous. Cancer lung

nicotine. Even 0.07gram of nicotine in Healthy Iung

4 Star Biology Practical Notebook 10th (Federal Board)

 Viva Voce 26 QA Short Questions and Answers
the following Questions.
Answer
What arethe main cffects of smoking?
i. Cancer of lungs, kidney, oral cavity,larynx, breast, bladder and pancreas.
Ans.
i. Damage to air passage which leads to emphysema.
ii. Effcctscirculatory system,causes increase in number of platelet and
arteriosclerosis.

iv. Smokers are at a two to four times greater risk ofTB and four times of
pncumonia.
V It also induces hcart diseases.

are the effects of tar on lungs?

O.2. What
i. Itcauscs cancer of the lungs.
Ans.
ii. Damages the air passageway which leads to emphysema.
i. Kills the cclls of air passageways.
people
O.3. Write three measures taken by the government to discourage
of passive smoking?
from smoking and to reduce harmful effects
Ans. i. Governments to stop tobacco advertising.
ii. To prevent young
people from taking up smoking.
and acro
iii. To allocate and nonSmoking zones in trains buses
smoking
planes.
beneficial?
Q.4.Is small quantity of nicotine speeds up the activity of the
in blood stream
Ans. Small quantityof nicotinc
it is useful.
inthis way
nervous system, so
smokers?
of heart attack among
more risk arteries
O.5.VWhy substance in the
there is
i.c. built
up of fatty
atherosclerosis
Ans. Smoking causes arteries and
hencedecreasing
blocks the flow of blood into coronary
whích
heart discases
such as angina pectoris,
As a result the
oxygen supply to
heart.
than the non-smokers.
problems becomes grcater
coronary arteries
tobacco contain?
Q.6. What do the leaves of nicotinec.
contain
The lcaves of tobacCo plant
Ans.
the
the activity of
Q.7.Is nicotine useful? blood stream speeds
up
Smallquantity ofnicotinein the
Ans. way, it is useful.
so in this
nervous system
blood can be
Q.8. How it is harmful?for health even 0.07 g of
nicotine in

Ans. Itis very dangerous

poisonous.
are the effects
of tar on lungs?
Q.9, What cancer.
respiratory
organs and cause
Ans. They kill

/ Experiment 26
15
Gaseous Exchange

Homeostasis /Experiment 27 17
 chapter

Date
15
EXPERIMENT Recording the heights
Inheeritance

of class
20

34 predict
presentation
which

heightsin graphical form

(either
fellows
of
kind
the
of variationfellows
data of
isit to
and
class

or bar chart).
histogram

it
All of

diferences

two kinds
us belong tothe same species
that are observed

()Continuous
among individuals
i.e. Homo

() Discontinuous
sapiens,

within
yet each one
a species
variations.UC0o
are called
of us looks

dS
variations.
different.

Variations
These

are
are of

of
variations

about 1. ContinuouS variations

Continuous variations areeven gradation within a population.Height in humans is a
good example. If
in population,the height each adult is measured and a histogram constructed
being
of
a
equal, it will
Learn show a curve of normal distribution (Gaussian curve).

Variation is inheritable only if it is due to genes. Height in man is only partially genetically

controlled, any effects caused by the environment cannot be inherited. In the case of
height, many

genes contribute to the character, for example, those controlled by the environmental
factors may be
equally diverse, like the effects starvation, malnutrition, disease andlack of exercise. The example
of
of
continuous variations are height, skin colour, inteligence in man and Kernel colour in corn etc.

2. Discontinuous variations
Discontinuous variation in populations can be seen where the individuals fall into two or more distind

groups with respect to a particular character. It usually occurs where there is a completely dominant

and recessive character within a pair ofob

400 - 400
contrasted genes. Height in pea plants,

investigated by Gregor Mendel, is an example 360 360

discontinuous variation. This particular plant

of
320 320

character is controlled by a single pair of genes

240 240
and the environment has very little over-all

effect on it within a large population.Other 200 200

example of discontinuous variation are Tongue

l60
l60

rolling and blood groups in human.

Histogram
120
oDo 120

The graphical representation of the data of a 80 80

hereditary trait is called histogram. In a

40 40

histogram of hereditary data, the horizontal

axis showsthe range of different phenotypes 156 160 165 170 175 180 185 190 Rollers + Non-roles

Height (cm)
of a trait and the vertical axis indicates the and discontinuous
variatics
b.
2 Histogram of continuous variation

number of individuals in the population.

52 Star Biology Practical Notebook 10th (Federal Board)

 EXPERIMENT

part
Recording the heights

o Measuring tape Graph paper

Material

Procedure
1. Measure and record the heights of all the students of your class in inches.

2. Now arrangethe heights in order of magnitude and make a frequency table. Ihe
table should show the height ranges as follows:

(Students to measure the heights and find the number of students selected and fill the

following table).

FREQUENCY TABLE

Groups o Height (Ronge inches)utuo Frequengy (No.of students) a he

in
Less than 55inches bos collon srooo0bslo
2 56-58 inches

3 59-61 inches

4 62-64 inches

5 65-67 inches

6 68-70 inches

7 71-73 inches

Observations and Calculations

Construct a histogram from the above data.

Inheritance /Experiment 34
 explain
what
your histogram,
Concuions By visualizing height.
trait is human
type of

tongue
EXPERIMENT
variations in
part Discontinuous
in man
brolling

graph paper
students
satena

It is
Procedure discontinuous
variation. dominant trait
of
is a an example
Tonguc rolling in man when they extend
it Out of their
U shape
distinct
its tongue into
a

and one can roll

called rollers.
mouth. They are Count the number of
to try to roll his tongue. 'tongue-
of your class
Ask cach student and draw your own
data
rollers and tabulate the histogram.
rollers' and non-tongue

Observations

Non-Tongue-rollers
Tongue-rollers
(NTR)
(TR) 60
50
40
students
of
30
20
Numbers
10

Tongue Not tongue

rolling rolling

Histogram of tongue rolling of 60 students

(Fig.

Viva Voce 34 QA) ShortQuestions and Answers

Answer the following Questions.
Listthe different continuous
variations in plants.
Q.1.
mass in Gram etc..
Ans. i. Seed colour inwheat grains. ii. Seed
iv. Size of shoot or root.
iii. Fruit mass in oranges ctC..

54 Star Biology Practical Notebook 10th (Federal Board)

 Count the number of "tongue-rollers"and non-tongue-rollers? in
your class and tabulate the data.
Students should count the number of tongue-rollers"and “non-tongue
Ans.
roller" in the class and tabulate thedata.

Who are tongue rollers?

Q.3.

An6. People who can roll their tongue into U shape when they extend it out of
their mouth are called tongue rollers.

4. Give examples of
i. Tongue-rollers
common discontinuous variations in humans.

Ans.
ii. Blood groups in humans
iii. Rh factor +ve, -ve
iy male and female sexes (gender).
Frece or attached car lobes.
V.
0.5.What is a histogram? trait is a
of frequency distribution of
a hereditary
Ans. The graph representation

called histogram.
of geneticvariation?
O.6.What is the ultimate source
Ans. Mutation.

Q.7. Define frequency?

an event takes place.
Ans. It is a measure of how often

O.8. What is a variable? measurable variation e.g. height in

that showS
Ans. Itis a property or quantity
man.

Q.9. Is variation inheritable

No, Variation is heritable due to genes.
Ans.
trait?
or discontinuous
Q.10. Is human height a continuous
trait.
Ans. It is a continuous varying
varying trait?
a continuous or discontinuous
Q.1l, Is tongue rolling
It is discontinuousvarying trait.
Ans.
varying trait.
Q.12. Give an example of continuous
Ans. Human height.

do you mean by geneticvariation?

Q.13. WWhat
between individuals most commonly
Ans. Occurrence of geneticdifferences
is known as genetic variation.
studied in species population

Inheritance / Experimer
 chapter Homeostasis

of the
EXPERIMENT Examination
Date kidney (Sheep
structure of
20

27 kidney/model).

of sheep kidney
box O Models / charts
O Dissection
kidne Hand lens, board
Aateri O Preservedsheep
chloride
O 1% solution of sodium

step

step
step

half kidney
Cut the kidney
Sheep's kidney

CorteX

renalcapsule

medulla

ureter
pyramids

renal hilus

papillae

renal pelvis

minor calyces

Dissection of sheep's kidney

6 Star Biology Practical Notebook 10th (Federal Board)

 Procedure
1. Obscrve the different parts of the sheep
kidney from the chart / model provided
to you.

2. Obtain a fresh kidney ofsheep and remove the fats to observe its external
structure and cxpose the ureter, renal artery and renal vein.

3. NoW massage thekidney gently in warm saline water (1%solution of sodium

chloride), in order to empty its
vesscls.
4. Cut thc kidney longitudinally through the center, with the help of a sharp razor
and obscrve it internal structure by
the help of a hand lens.

Observations

Draw your observations,regarding the external and

internal structure of the sheep
kidney.

1. A sectionthrough the kidneys shows an

outer darker region or cortex and a
lighter inner region,the medulla.

2. A tube, the ureter runs from cach kidney to the base of

the bladder in the lower
part of abdomen.
3. The kidney tissues contain many smallertubulescalled renal tubules.
4. Renal artery bring oxygenated blood to kidney.
5. Renalmedulla consists of several cone shaped areas callcd renal pyramids.
6. Renal pyramids projectinto a funncl
shaped cavity called renal pelvis.

There are two kidneys. Each kidney a bean known as renal capsule.
is is
The outer region of
shaped organ that is enclosed in a fatty the kidney is called renal cortex. It is dark red in

menbrane. They are attached tothe dorsal color and lies just below the capsule. Renal
body wall within the abdominal cavity, one on medulla
nogP is light in colour and is the inner region
each side of the vertebral column, jus above the of kidney. It lies just deep to the cortex. It is

waist-line. The left kidney is slightly higher than segregated into triangular regions known as the
the right one. renal pyramids, with convergein an empty space
The concave side of the kidney faces the called renal pelvis.

vertebral column. The depression in the center The kidneys have two main functions:
of this surface is known as hilus. The hilus 1. Removal waste products e.g. urea,
of
uric
provides a place for the renal artery, renal vein acid.

and nerves to enter and leave the kidney.

2. Regulation of body fluid by controlling the
A smooth semitransparent membrane that water and mineral salt content.
adherestightly to the outer surface of the kidney

Homeostasis /Experiment 27 17
 Viva Voce 27 QA Short Questionsand Answe

Answer the following Questions.

unit of kidneys?
Q.1 wWhat structuraland fnctionál
is
functional unit of
kidneys is called nephron.
and
Ans. The structural
concave!
column? Convex or
side of kidney faces vertebral
Q.2. VWhich
kidney faces the vertebral
column.
Ans. The concave side of the
functions of kidney? amnount of
Q.3. VWhat are the main the formation of urine and
also regulates the
Ans. Its main function is

body.
water and salts in the
section of kidney,
why is the outer region darker
Q.4. In the longitudinal
than the inner region? more
has more blood supply,
Ans. the outer region i.c. the cortex capsules for
Because
bundles of capillaries in Bowman's
and
capillarics
numerous
called glomeruli.
pressurefiltration
the regulation of blood pressure?
Q.5. What is the role of kidneys
in
If too little
pressure by excreting excess of sodium.
Ans. Kidncys regulate blood
increases. It also
plays an important role in
excreted, blood pressure
cnzyme renin. When blood
sodium is

nornmal blood pressure by secreting stream

maintaining secret renin into blood
below normal level, kidneys
pressure falls
which in turn raises blood pressure.

Q.6. VWhat is the number of kidneys?

Kidneys are two in number.
Ans.

Q.7. What is the colour of kidneys?

Ans. Dark reddish brown.

Q.8. Name the artery and vein that leads to kidneys.

Renal artery and renal vein.
Ans.
kidney and passes to bladder.
O.9. Name the tube that arises from each
Ans. Ureter.

between cortex and medulla?

Q.10. How would you differentiate
and medulla is inner thicker and lighter
Ans. Cortex is the outer, darker region
ZOne.

Q.1l. What is glomerulus?

network of capillaries in Bowman's capsule.
Ans. Glomerulus is

Q.12, What is bladder?

The bladder is an extensible sacwith elastic tissues.
Ans.

18 Star Biology Practical Notebook 10th (Federal Boad)

 O.13. What is the function of bladder?
Ans. Storage of urinc.
O.14 What muscles control bladder?
Ans. Sphincter muscles.
Q.15. What is pelvis?
Ans. Pelvis is the enlarged or cxtended portion of urcter inside kidney.

Q.16. Name the units of

excretory systemn.
Ans. Nephrons are the units ofexcretory system.
Q.17 Define Nephrons.
Ans. Nephrons are microscopic,coilcd tubules.

Q.18. Name differentparts of

Nephron.
Ans. A nephron has three parts:
a. Bowman's capsule
b. A coiled portion
C. U-shapcd, Henle's Loop
Q.19.What structures constitute cortex?
Ans. Cortex is mainly composed of Bowman's capsule and coiled portion of the
nephron.

Q.20. What structure make up Medulla?

Ans. Medulla consists of loops of Henle and collecting tubules.

Homeostasis /Experiment 27 19
 chapter Gaseous

Date
20
10
EXPERIMENT Activityto
compare the
rate at rest
and
Exchange

24 4
breathing
after exercise.

O Stopwatch
oterials

Procedure will act as

an
In cach group, onc student
groups,
performed in of the group.
sdctiVity will be of other students of the
observer who will record the observations of other
students
rate
the breathing
1. Ask the observer to countand record
group in the resting position. for five minutes.
walking)
to do some light exercise (C.g.
2. Tell the students
rate Precautions
to count the breathing
3. Again ask the observer
and note down the observations. from
to do Students suffering
the students
rest of 15 minutes asthma and heart problem
tell
4. After a
(e.g. running) for five should not take
part in this
some strenuousexercise
to record the exercise.
minutes and ask the observer again

breathing rate of the group.

Count
breathing rate
with stopwatch

An observer willnote the breathing An observer note the breathing

will

rate of the student while at rest. rate immediately after the student

has stopped running.

Breathing rate at rest and after exercise

Star Biology Practical Notebook 10th (Federal Board)

 of breaths per
The number minute
it rate. One
is called
activity (rest or exercise).
inhalation
breathing (taking in air) and
exhalation (giving out air) is one During inhalation air is taken in through nasal
one breath,

takes place by the passage which leads to Trachea. Posteriorly the

Breathing movement
about hs and diaphragm. During inhalation the
of
lungs,
Irachea ivides into wo bronchi, each bronchus
contracts andribs expand
enters the lung of its side. Each lung is a spongy
diaphragm which make
balloon-ike structure with millions of thin-walt
Thusthe lungs expand
cavity larger.
chest and the sare nr alver which are richly supplied with
Learn
air from
the atmosphere rush hes into
the lungs.
During exhalation the diaphragm blood capillaries. Here the exchange of O, and
and iu:
totheir normal position CO, takes place. This experiment is concerned
return thereby decreasing
with the change in the breathing movements
chest
the volume cavity. As
of
a result the lungs
moves alongwith the change in body position, that is
contract
and air Out
the lungs.
of
resting conditionor in mild, or the strenuous
Breathing rate dependson several factors
exercise. Accordingly there is change in breathing
such as altitude, lung capacity, health and level of rate.

Observations
Students should fill the following table.
Table: Breathing Rate

No. At rest
Student After Light After Strenuous Exercise
Exercise

1.

2.

3.

4.

Conclusions
Compare all these observations and interpret
the results.

(Studentsshould compare the breathing rates

from the observationsfilled in the above table

and then write the results).

Viva Voce 24 QA) Short Questions and Answers

Answer the following Questions.

Q.1. What is the stimulus of breathing? (i)carbon dioxide concentration in

blood, carbon dioxide concentration in the alveolar air, (ii) oxygen
(ii)
air!
concentration in blood or (iv) oxygen concentration in the alveolar
Ans. The stimus for breathing is the high concentration of carbon dioxide in the
blood.

Gaseous Exchange /Experiment 24 9

 after exercise.
Why?
rapid and deep
Q2. The breathing becomes
after exercise, more CO, is produced and
activity i.c.
Ans. During muscular to remove
deep especially
breathing becomes rapid and CO,out
conscquently of oxygen.
of large amount
and also for the intake
in the composition of the inhaled and
Q.3. What are the main differences

exhaled air? exhaled

between inhaledand
air.

differences
Ans. Following are the mai
air
the inhaled and exhaled
Differences betwveen
Exhald Air
Inhaled Air
Features
16%
21%
Amount of oxygen 4%
0.04%
Amount ofcarbon dioxide
79% 79% (Remains the same)
Amount of nitrogen Saturated
Variable
Amount of water vapours Almost none
Variable
Amount of dust particles
your muscles get fatigued.
How it happens?
exercise,
Q.4. After vigorous Our muscle cells produce instant encrgy by
Ans. demands energy. a lot of
Exercise can generate
a living in cell

brcaking down ATP.The mitochondria

But Oxygen is scarce during
breaking down sugars.
ATP's acrobically by through an
to produce energy
System adopts different strategy forme
Cxercise. is less than the
glycolysis in
which energy produced
aerobic path called occurs which causes
muscle fatigue.
of lactic acid
and hence accumulation
minute?
Q.5 What the normal breathing rate per
is

Ans. It is about 14 -l6.

afterwalking in laboratory?
Q.6. What happened in breathing rate.
Ans. There was slight increase
up and downstairs)
the change in breathing rate afterrunning
Q.7. What was
increased.
Ans. The brcathing rate
region of breathing?
Q.8. What is the controlling located in medulla
of brain.
Ans. It isthe “Breathing centre"
the body parts?
O,transported from lungs onward to
Q.9. How is
which now becomes Oxyhaemogiobin.
Ans. It is carried by hacmoglobin of blood

or vein concerned with lungs?

Q.10. What namne is given to the artery
Ans. It is called PULMONARY.
and deep
the breathing.becomes rapid
Q.1l.After exercise,why and breathing becomes
rapid and
activity CO,is produced
Ans. During muscular of O,.
CO, out, and also for intake of large quantity
deep especially to remove

(Federal Board)
Notebook 10th
10 Star Biology Practical
 Reproduction
chapter

Date
120 EXPERIMENT
14
Observation of binary fission

30 of amoeba using slides,

photomicrographs or charts.

Omicroscope pre pared slides

Materias
and charts showing photomicrographs
binar fission in Amoeba

Procedure
1. Study the stages

photomicrographs or charts.
of binary fission in
Amoeba from
1.
A Precautions

Handle the prepared

2. Observe the
prepared slide slides very carefully.
of binary fission in
Amocba under the low and 2. Do not lower the lens
high powers of of the microscope
microscopc.
withoutlooking into
3. Now locate the different the eye piece. Bring it
stages of the binary
fission. lower very slowlyand
gradually.
it
In binary fission,
the simplest form of
asexual reproduction, the
parts that are about parent organism divides into
equal. Each of the two
daughter cells becomes a
normal size. separate individual and
growsto
about
Noparent is left in this method of reproduction
because the parent has
Binary fission is the usual method of become two individuals.
reproduction among one-celled organisms e.g.
paramecium etc..
Binary fission takes place when amoeba,
the conditions are
fission takes place within 30 minutes favorable. In Amoeba, binary
Learn
at 20°C.

nucleus

nuclei Two
daughter
Amoebae

Parent
Nucleus
Amoeba divides
Cytoplasms dividesh
4 Binary fission in Amoetta

Reproduction /Experiment 30 35
 Observations
fission and draw thelabeled
the various stages of binary
Observe and identify diagrams,.

Amocba is ready for division.

1. A mature ccll of

is contains nucleus and

membrane and cytoplasm.
The cell is bounded by cell
in sh.
none or less spherical
pseudopodia and
is
its
2. Amocba now withdraws
two daughter nuclei by
mitosis.
divides into
3. Nucleus
divides into two.
4. At the same time cytoplasm
are also divided equally.
contained in the cytoplasm
5. The structures
of cell and results in the separation of
constricts in the center two
6. Cell membrane

daughter cells.
increase in size and gain maturity and are again
7. The resulting daughter cells

for division.

Conclusions Amoeba divides two daughter organisms

into

of equal size by binary fission. They gain

and are again ready for division.
maturity

Viva Voce 30 Q&A Short Questionsand Answer

Answer the following Questions.

Paramecium. Note down
permanent slide of binary fission in
Q.l. Obtain the
binary fission of Amoeba.
the difference, if any, from the divide, followed by
nucleus and micronucleus
Ans. In Paramecium both mega
cytokinesis.
into two nuclei followed by
In Amoeba, the single nucleus divides

cytoplasmicdivision.
binary fission is? Mitosis or Meiosis!
What type of cell division,
Ans. Mitosis.
Amoeba produces many cells
Q.3. During unfavorable conditions,the parent
type of fission is it?
at the same time. What
Ans. It is called multiple fission.

Q4.Do resulting resemble their parents?

cells
in parent Amoeba but aresmallerin size.

Ans. Yes, they do have all structures as

Q.5. What structuresdivide in binary fission?

cell membranc etc..
Ans. All structures like nucleus, cytoplasm,

takes place?
Q.6.In what kinds of organisms this type of reproduction
Ans. It takes place in smaller organisms like protozoans.

Notebook 10th (Federal Board)

Star Biology Practical
 Date EXPERIMENT
20 Observation of budding in

31 yeast from prepared

slides.

O prepared slides showing budding in yeast

Aateria.
microscope

Procedure
Precautions
1. Observe the prepared slide of budding in yeast
under low and high
powers of microscope. 1. Clean the lens before
2. Observe and identify diferent stages of
use.
budding
in yeast and draw the labeled 2. Handle the
diagranms.
microscope very
carefully.

Observations
Ifwe examine structure of veast we find that a thincell wall encloses the cytoplasm,

which contains a nucleus and a vacuole. In the cytoplasm are granules of

glycogen and
other food reserves.

1. Inyeast, asexualreproduction is characterized by budding.

2. Budding occurs at a predetermined spot on
cell wall.

3. At that spot, cell wall bulges out to form a

4. The nucleus divides into two daughter

5.
alongwith other organclle migrate
The bud is
bud.

nuclei and

separated from the mother

into the bud.

cell.
1. Budding occurs at
predetermined
Do You
Know
spots on
?
cell

wall.
6. The bud may remain attachcd and produce 2. Parent cell may form more

another bud. than one bud ata time.

it Yeasts are unicellular fungi which are found on form a new cell similar to its parent cell. The
the surface of fruits, in soil, water and even on buds formed may break off and live

dust in the air. Yeasts reproduce asexually by

independently or it may remain attached forming
about budding in which a bud develops as a small a colony.
outgrowth on parent's body. The nucleus of the nucleus bud

cell divides in two by mitosis. One daughter

nucleus passes into bud. The bud grows bigger
Learn

and bigger until it acquires the size as the

"parent" cell. The bud containing the new

nucleus and other organelles then breaks off to

budding in yeast

Reproduction / Experiment 31 37
 the parent organism
occursin which
In yeast asexual reproduction divides
as small outgrowthsor into
New individuals develop buds on
unequal parts. the
parent organism.
Some buds remain attached
outer surface of the withthe
few brealk off to live independenthv
parent forming a colony while a

Viva Voce 31 OA Short Questions and Anst

Answer the following Questions.
daily life?
Q.1 What is the role of yeast in your grcat importance is of
in our daily life. It
Ans. Yeast Saccharomyces cereviside is
Similarly it is used by vegetarians
to produce bread, beer and wine.
used for
which is low in sodium and fat but high in
nutritional supplemcnts protein,
vitamins and minerals.

fission.
Q.2. Differentiate between budding and binary
of the parent.
devclops on the body Thebud
Ans. In budding asmall outgrowth
grows for sometime ad thcn separates
to give risc to a new individual e:
cytoplasm divides arbitrarily into
hydra. In binary fission, nucleus and
similar halves.

any multicellular organism in which

Q.3. Suggest the name of budding occurs.
Ans. Hvdra.

budding and multicellularorganisms.

Q.4. Compare in unicellular

in unicellular organisms an outgrowth is formed on the cal

Ans. During budding

The nucleus divides into twO and one of them moves into
surface as a bud. the
for sometime and ultimately separatesas an
bud. The bud grows independent
individual, as in yeast.
outgrowth or a bud is formed on
In multicellular organisms, a multicellular
and then separates as an
the parent body which grows for sometime
independent multicellular organism.

Q.5. In nature where is yeast found?

Ans. In nature, it occurs in various fruits.

Q.6. Is the plant body haploid or diploid?

Ans. Diploid.

Q7. What is budding?

Ans. It is a phenomenon of asexual reproductionin which an out growth appears in

the form of bud.

Q.8.VWhat are yeasts?

Ans. Yeasts are rather unusual family of fungi.

Q.9.What does body of ycast is made up of?

few yeast contain hyphac but in most cases body is made up of

Ans. Only a

spherical cells.

38 Star Biology Practical Notebook 10th (Federal Board)