EXPERIMENT FOR SPOTTING-17

Study of Commnon Disease

Causing Organisms
INTRODUCTION

Identification of specimens and prepared slides is one of the important part of biological
practicals. Specimens of some common disease causing organisms bones and prepared slides
are generally used for this purpose.

(i) For a specimen examine it carefully with naked eyes as well as with the help of hand
lens. Draw its labelled diagram and write down the features of its identification.
(i) For prepared slides observe the slide through microscope carefully. Draw its labelled
diagram and write down its features of identification.
3. Ascaris
Identification. Ascaris lumbricoides (The giant intestinal roundworm)
Disease caused. Ascariasis.
 MANUAL IN BIOLC
92 COMPREHENSIVE
LABORATORY
OLOGY
Comments and is more
re commo
common in
beings
. I t is an endoparasite of the small intestine of human
children. than the male.
female is longer
2. The animal shows sexual dimorphism. The
3. The posterior end of the male is curved ventrally.
about one
4. In female, the genital aperture is present on the mid-ventral line att about one thid thir
of the length from the anterior end.
5. In male from the cloaca two equal chitinous spicules or pineal setae project which

help in copulation.
Symptoms
1. Generally a large number of adult Ascaris worm infest a single host, and obstruet
the intestinal passage and thereby cause abdominal discomforts like colic pains.
2. The patient may also suffer from impaired digestion, diarrhoea and vomiting.
3. In children mental efficiency is affected and body growth is retarded.

Mouth
-Mouth

Excretory
pore

Female
genital
Lateral Line aperture

Cloacal
aperture

Anus
Pineal setae
(spicules)

Male
Tail
Female
Fig. 17.4. Ascaris.
 Objective. To isolate DNA from available plant material such as spinach leaves
green pea seeds, papaya etc.

REQUIREMENTS
Plant material (such as spinach leaves, green pea seeds or green papaya), mortar and
pestle, beakers, test tubes, liquid detergent, non-iodised sodium chloride, distilled water, meat
tenderizer or papain solution/juice of papaya/pine apple juice, 95% ethanol, spool etc.

PREPARATION OF SOLUTIONS

Detergent salt solution is prepared by adding 10 mL liquid detergent and 10 g of non-

iodised sodium chloride to 90 mL of distilled water.
Meat tenderizer solution is prepared by adding 5 g of tenderizer (enzyme) to 95 mL of
distilled water (Juice of papaya/pine apple, filtered through muslin cloth can be used as
substitute for meat tenderizer).
5% NaCl solution is prepared by dissolving 5 g of non-iodised sodium chloride in 100
mL of distilled water.
. Chilling of ethanol must be done by keeping 95% ethanol in plastic bottle in the freezer
over night.

54
PROCEDURE

Take 5 g of the
plant tissue (spinach leaf/ green pea
seed/green papaya) and grina it i
the mortar by adding 10 mL detergent, salt solution and filter it through musiin
ciou
Take 10 mL of the filtrate, add 3-4 mL tenderizer/papaya juice and swirl the test uD
by holding the tube between the two hands to mix the contents.
Pour 10 mL chilled ethanol carefully down the side of test tube to form a layer on the
top of the content; let it stand undisturbed for about 3 minutes.
Using the glass rod stir gently through interface of the two layers to collect the
tate of DNA and place it in a test tube with 5% NaCl or distilled water.
precipi
The quantity of DNA present in the given plant material can be estimated through
spectrophotometer.

Fig. 8.1. DNA that separates out can be removed by spooling (spool = reel for winding yarn).

OBSERVATION
The addition of ethanol to the solution causes DNA to precipitation. The DNA fibres
appears as white precipitate of very fine threads on the glass spool.

PRECAUTIONS
1. The plant material should be washed throughly with distilled water to remove any dust
and dried by blotting before weighing.
2. All the glasswares used must be thoroughly cleaned and dried.
3 The chemicals and enzymes used for the experiment must be of standard quality which
should be manufactured by standard pharmaceuticals.
 Objective. To study the flowers adapted to pollination by different agencies
(wind, insect and birds).

REQUIREMENTS
Fresh flowers ofmaize or any other cereal/grass, Salvia/Ocimum and Brassica (mustard)
forceps, hand lens, slide, needle etc.
PROCEDURE
Note down the
Place the given flower on a slide and observe it with the help of hand lens.
adaptations of the flowers meant for pollination by the external agencies.

Maize Flowers (Anemophilous or Wind Pollinated Flowers)

The flowers of maize show following adaptations for pollination by wind.
1. The maize plant is monoecious and bears unisexual flowers. The male flowers are born
in terminal inflorescence while the female flowers are born in axillary inflorescence.
2. Flowers are small and inconscipicous.
3. The flowers are colourless, odourless and nectarless.
4. Flowers are produced above the foliage or placed in hanging position.
5. Both the stigmas and anthers are exerted (i.e., hang outside the perianth).
6. Anthers are versatile, and pollen grains are light, small and dusty.
7. The pollen grains are produced in very large numbers.
8. Stigma is hairy, feathery or branched to cateh wind born pollen grains.
 Male flowers

Tassel

Pollen grains

Cob Versatile
anther
Elongated Feathery
styles stigma
Pollen grains Ovary
of another plant
Stigmas
Fig. 9.1, Anemophily in maize. Fig. 9.2. Feathery stigmas and versatile
anthers in a flower of grassS.
Salvia Flowers (Entomophilous or Insect Pollinated Flowers)
The flowers of Saliva show following adaptations for pollination by insects.
1. The flowers are showy or brightly coloured for attracting pollinating insects.
2. The flowers are born in verticellaster inflorescence to become conspicuous
3. Flowers secrete nectar to feed visitinginsects. Nectar glands are placed in such a position
that an insect must touch both the anthers and stigmas.
4. The flowers have landing platform for the insects.
5. The flowers are protandrons with bilipped corolla and have turn pipe or lever mecha-
nism.
6. Each stamen has long connective which bears a fertile anther lobe at the upper end andd
sterile plate like anther lobe at the lower end. 1The two sterile anther plates block the
path of insect.
7. As the insect moves inward a young flower in search of nectar, its head pushes, the
anther plates and forces the fertile anther lobes to strike against its back.
8 In older flowers the style brings the stigma in sucha position that it brushes against the
back of and
insect collect pollen grains brought bytheinsect from a young flower
 Closed stigma
Fertile
anther lobe d s9191998

Shedding of
pollen grains
on the back
of insect

Sterile B
A anther lobe
Stigma
Nectariferous Mature receivin9
disc stigma pollen grains
7 from the back
of insect

C D
Withering
anther
 Objective. To study Mendelian inheritance using seeds of erent colou
ditferent colou
size of any
plant.
REQUIREMENTS
r e a seed
sample, enamel tray, petri dishes, notebook, pencil/pen.
PROCEDURE
1. Take lot of
a about 100
pea seeds in an enamel tray.
2. Separate out round and wrinkled seeds and put them in
3.
separate petridishes.
Note down the number of
round and wrinkled seeds and calculate their
ratio. approximate
Repeat the process for the other contrasting trait of the seed i.e., yellow and green
colour
OBSERVATIONS
Present your findings in the form of a table
given below. Data related to two findings is
given in the table, record your finding in the same
way.
Table 14.1
S. Characters/Traits of seed Total no. of No. of seeds showing con-
No. Approximate
seeds observed trasting form of the trait ratio
1. Seed shape (Round/Wrinkled) 106 80 (Round)
: 26 (wrinkled) 3.07:1
2. Seed colour (Yellow/Green) 110 83(Yellow): 27 (Green) 3.07:1

CONCLUSION
The contrasting forms in both the traits of pea seed (i.e., seed shape and seed colour
show an approximate ratio of 3 : 1. This ratio is exactly the same as obtained by Mendel tor
monohybrid crosses and indicate that the dominant and recessive forms of seed shape and seed
colour exist in the ratio of 3 : 1 in the population of pea seeds.

PRECAUTIONS
Take a sufficiently large number of seed lot for analysis to minimise the error.
1.
2. Observe the contrasting form of the trait carefully.
 Objective. To study and identify the stages of gamete development in mouse
(mammal) i.e., T.S. of testis and L.S. of ovary through permanent slide.

REQUIREMENTS
Permanent slide of T.S. of testis and LS. of ovary, microscope.

PROCEDURE
Fix the permanent slide under the microscope. First observe it under the low power and
then under high power.

OBSERVATIONS
T.S. of Testis
.The testis of a mouse (mammal) is covered by a thick fibrous tissue called tunica albuginea.
2. The testis consists of numerous seminiferous tubules embedded in the interstitial tissue.
3. Various types of germinal cells are present from outside towards lumen in the following
sequence.
Spermatogonia > Spermatocytes Spermatids Spermatozoa > Sperms.
4 Between the germinal cells, pyramid shaped cells called sertoli cells are present.

65
 COMPREHENSIVE LABORATORY MANUAL IN
BIOLOGY-X
5. A large number of spermatozoa with their heads embedded in sertoli cells are
the lumen of seminiferous present in
tubule.
6. The interstitial tissue also contain leydigs cells, which
produce male
testosterone.
sex
hormone
Visceral
peritoneum
Tunica
albuginea
Blood vessel
Spermatozoa
Seminiferous Spermatid
tubule
Secondany
Sertoli cell spermatocyte
Primary
Connective spermatocyte
tissue Sertoli cell
Germinal epithelium
Spermatogonia Spermatogonium
Spermatocytes-
Spermatids
Spermatozoa
Interstitial
cells B
A
Fig. 11.1. A. A Part of transverse section of testis of mouse (mammal).
B. Sectional view of a part of seminiferous tubule (enlarged)

V.S. of Ovary
1. A mouse ovary is a solid structure bounded by germinal epithelium followed by a thick
layer of fibrous tissue, the tunica albuginia.
Egg nest
Primary follicle
Cortex
Secondary
follicle
Blood
vessel
Tertiary
follicle

Visceral
Mesovarium peritoneum

Graafian follicle
Corpus
albicans

Corpus luteum

Medulla
Ruptured follicle

Fig. 11.2. A section of ovary of mouse (mammal).

CORE EXPERIMENTS
67

2. The ovary consists of outer cortex and inner medulla.

3. The medulla contains many rounded or oval bodies called ovarian or Graafian follicles
at various stages of development.
4. The medulla also contains blood vessels, nerves fibres and some smooth muscles.
5. Each follicle contains a large ovum surrounded by many layers of follicle cells.
6. The cortex contains young and mature follicles.
7. The cortex may also contain a large mass of yellow cells termed corpus luteum, formed in
an empty Graafian follicle after the release of its ovum.

PRECAUTIONS

1. First observe the slide under low power and then under the high power of the micro-
Scope.
2. Use fine adjustment of the microscope for focussing the slide under high power
 Date

Expt. No. 6 PageNo.12

Aim=loshndy Ibe palleo aeminstonsa aSlide.

Mateials naquiced= Soasaanl1amer ike lilyTetunia ek
colcinm_aiiraeborícacid Suczoseydiákned
Hatca Pebd deah Sldes, cave4Slips ush
neede1 micsosceope aná halaoce

Pioctpe olleo arains oz_miccaspgres ore nsoo

Spneaieal CHuc e g Nhich meosoe abaut
E DO mitramete4a fa dtacneterlnnauie nas
geimioale oo ne CompaHble Skama o necapely
A 1he laooatury hetrga1mina ioa mediuen natsh-
Coataiog nubieieesadokal Par pollao eccatnatro
Eadh pallen qLata te 2urauadad u t layersd-
hia1. he ouler Wa S a l e d o xioe
_daA he oner eallid ldtioe h e eyiaa has
pIamfneotopestores calied ernpaieSDuaia9
t
ermiao Hoo ne inhoe aa alea97aio
meqes out_as palueo aeèdmauqd one 1ne.
gea pores

Procedace
Dssalua lag Sacraae3a ag caleum nitale aod
loma_hanteootdiA
Lomo laoml diskLed Nate
20re a A a t i es soloEbo

Putadrap oI siÁedtmediun ia lheCoote

Desde od ihas breok Ina_Aotner
Teacher's Signature
Exine

Intine
Tube
Nucleus

Generative Pollen
Nucleus Tube

B Germ Pore D
Sperm
Nuclei
Tube Nucleus
Tube Nucleus
 Date

Expt. No. Page No. 3

nature LOwerand dugt 20lea qatos ioine don

laco aeouer i p on ne SlLde aod leou 011amntecs

Ouene tde usde microscope caoot In talL
n Palln C1oa inS fhat hau or minate d

( Aqala chanqe ine pasthaa a 1ne siíde and cauat ine nDa
pollo germioatrd a g oare mitroscapafe1

Abseua koo ein seoeAhoi io antisat mediun-

alle0asains eaminaBe and pu 1hpoll.atube.
Adme ne plo psed as sauceo polen i s -

KaultS Palleo g1oios naue oeeo jgUad qeaminated

j1É he sapsimeot

ecout200S
pucked laler3-

L Kde and cOveLsiipShound be claao

Sdes a m dijeveot awrs ehaud be

lanelled pza

Teacher's Signature
 Date

Expt. No. Page No. - 6

Atmlo Study plaat papuiahion deo3ly andaeqmaeuby

vadxat me fhod

Matendol\s Reauired Cotoalnulon fhtady Nailg laammer

pencil and aper

iacple Deng!ty Tepre Se ot he nMericol stresadh a

Cerlaia plaotSpecies a he Commuatiy pez uott hrcane
nomhe d iodiuidual901 1hé Speies la 'any bait a1eaa
s tls dea'aely
Density=dtal nhmhera laduzduala1 s pacics ín a11 Samnliaq uailO
Jotal_ numher a gamp 1ioq 0atts Sudied

yeaueac
equeacu sCanceaned ilá lhc degrecaaiazaity1he
Occocaace c ladiuzdoal o 0 Gnecdes. taio a p 1ant
Coomluntiu requeacu is he number a Sampiiau uatt
Las 1o hhich a paikcular S eciosOccor

iequeneu No.oSampliaq nattsialwhích Gpetics Gccu Cn)

lo iana. o camplino oatt enapiaed shdy

Procoduxe 0]n lhe Selected Stle_aake_almxlm quadzat

Hih Ihe heip anatls ans thzeadsaad Ihaa 1s+ Ihe na.mes
ne piat `pe cies (|_Species snat Koawo maik mem
as sLae cies Asad stc
CoD t lhe_na al iasidaloeochSpecics aod rec.ad -
A covat papola de agitu a occUraace 9sno ula
(i Calcolahne equiacu accarence
Ihe oamulagiuen-
Teacher's Signature
 0Y
Y

Y
5
Y

Fra- A qvodrot wl Sob oni Is

 Date

Expt. No0.
Page No.

Oosezalfans
Ishal na PaPolokaa
edes
adrat|Q2adzat QuadatoinisdoalOeastu
3 FN xiad

IHimosa Rudica 15 /a-5 s-66

phaaia hirta 14 3 25 25/3 3 2

3.33 3 331
|kpdesaianaxa 10 10 3

SperaatcocoeaSp| 2 2 73 04g |3 337

uanadna dochuloa 53- 56 l12 -31.3 1o07

1 s 2.33|y:331
ysoposm.
lndapesm

3 33.
Ladtea moitt lora 3 3

Maunaceae V3133 | s 33

Stda xharatlalia 2 | 73 0:6e| Ys 3 3

EuphaBium 4 % 1.33s33
Odarowa

AaKantc Lmdata Ys 1.ss 337

Teacher's Signature.
Expt. No. Page No.

recaufons
hem 1emeni a a adraois Shonld be accunale

he SBzinq_o1 cozd Osedchoudna he-Uezu níc k-

Q0e indiutdua1 o_Q Shecies sb.auid loe coun1e oal4-

ance in lne _quddmt

Make Sae not lIne ve getahiao ts nat damaged lhile-

loyinohe quadrat

Teacher's Signature
Exercise 25


















Observations

1. Homologous Organs in Plants

(i) Tendrils of passion flower and thorns of pomegranate

Tendrils of passion
fruit and thorns of
pomegranate are Tendril
structurally and
functionally different
but they have similar
origin i.e. they arise
from axillary bud Thorn
(Fig. 25.1a & b).
(a) (b)

Fig. 25.1 (a) Tendrils of passion fruit (b) Thorns of pomegranate

21/04/2018
 LABORATORY MANUAL: BIOLOGY

Tendril Thorns (ii) Tendrils of Vitis and thorns of

Carissa
Tendrils of Vitis and thorns of
Carissa originate from the terminal
bud, but they are functionally
different (Fig. 25.2 a & b).

(a) (b)
Fig. 25.2 (a) Tendrils of Vitis (b) Thorns of Carissa
(iii) Tendrils of baloon vine
Tendril (Cardiospermum) and bulbils of
Agave.
Both are modifications of floral bud,
but they perform different functions.
Tendrils help in climbing but bulbils
are meant for reproduction
(Fig. 25.3 a & b).
(a) (b)
Fig. 25.3 (a) Tendrils of baloon vine (b) Bulbils of Agave
(iv) Scale leaves of onion and spines
of prickly pear (Opuntia)
Both the scale leaves and spines are
Spines modifications of leaves but are
structurally and functionally
different. Scale leaves of onion are
thick and fleshy and store food. On
(a) (b)
the other hand spines of cactus are
Fig. 25.4 (a) Scale leaves of onion (b) Spines of cactus defensive organs (Fig. 25.4 a & b).

2. Analogous Organs in Plants

Tendril
(i) Stem tendrils and leaf tendrils
All tendrils are analogous with one
another, being structurally and
functionally similar, irrespective of
their origin.
Example: Tendrils of pea and
tendrils of Vitis. Tendrils of pea are
Tendril modification of leaf and in Vitis it is
(a) (b) the modification of terminal bud
Fig. 25.5 (a) Tendrils of pea (b) Tendrils of Vitis (Fig. 25.5 a & b).

90

21/04/2018
EXERCISE 25

(ii) Thorns and spines

Thorns and spines are analogous structures being
defensive in function. Thorns are modifications of
axillary or terminal buds, and spines are (a) (b)
modifications of leaves. Fig. 25.6 (a) Modified root of carrot
e.g: Thorns of pomegranate and spines of (b) Rhizome of ginger
prickly pear.
(iii) Modified underground stems and modified roots Spine
Modified stems (rhizome, corm, tuber) are
analogous to modified roots (carrot, radish) as they
perform similar function of storage of food but their
origin is different. Rhizome of ginger, potato tuber,
(a) (b)
Colocasia are stems and beetroot, radish etc. are
Fig. 25.7 (a) Phylloclade (b) Cladode of
roots. (Fig. 25.6 a & b)
ruscus
(iv) Phylloclade, cladode and leaves
They perform the same function i.e. they
photosynthesise but phylloclade and cladode are
modifications of stem. Phylloclade of Opuntia,
Parkinsonia, Asparagus and leaves of any local
plant like mango are analogous organs.
(Fig. 25.7 a & b) (a) (b)
3. Homologous Organs in Animals Fig. 25.8 Fore limb of (a) human (b) bat

(i) Wings of birds, and forelimb of mammals/reptiles/

frog: All have the same bony elements (humerus radio-
ulna, carpals, metacarpals and phalanges), but
perform different (flying in birds, for holding or walking
etc. in other) functions. (Fig. 25.8 a & b) (a) (b)
4. Analogous Organs in Animals Fig. 25.9 Wing of (a) dragonfly (b) bird
(i) Wings of dragonfly/cockroach/butterfly and of
birds. (Fig. 25.9 a & b)
(ii) Mandible of cockroach and mandible (lower jaw) of
a vertebrate. (Fig. 25.10 c & d)
(a) (b)
Note: Students and teachers are suggested to discuss
Fig. 25.10 Mandible of (a) cockroach
more examples.
(b) rabbit

Questions
1. Suggest examples of homologous and analogous organs other than what are
given in the manual.
2. Why are stem and leaf tendrils considered as analogous organs?

91

21/04/2018