Its is useful for studying the experiments and practical uses

1. Biology Practical
Part B
Q. No. 4
Spotting
Std:- 12th
ACADEMIC YEAR 2020-2021

2. H.S.C - BIOLOGY PRACTICAL
Q.4 IDENTIFICATION (10 marks)
1 mark for each spot A To I
½ mark – identify
½ mark – comment
(Botany: A To F & Zoology: G To J)

3. A. Name the plant and comment on the floral adaptation for
type of pollination.
Maize plant -
• It shows floral adaptation for wind
pollination/ Anemophily.
• The flowers are unisexual and plant
is monoecious. Male inflorescence is
terminal while female inflorescence
is axillary.
• Flowers are small, unattractive ,
odorless, nectar less. Perianth is
reduced to two lodicules.
• Anthers are versatile; pollens are
light in weight & large in number.

4. Salvia -
• Flowers are adapted to Insect
pollination/ Entomophily.
• They are bisexual attractive & have
bright colored petals
• The nectar and the nectar glands are
present in flower and they are
situated in such a way that when
insect tries to reach the nectar gland,
it wings and body parts will definitely
touch the anther and stigma.
• Salvia shows blipped corolla. The
larger lip encloses style and stigma.
There are two stamens located at the
mouth of corolla tube.
• The pollination mechanism in salvia is
A. Name the plant and comment on the floral adaptation for type
of pollination

5. B. Identify and comment on the stage of Meiosis
Anaphase –I
• It is an important stage of meiosis-I, as
reduction division takes place in this
stage i.e. chromosome number is
reduced to half of the total number.
• spindle fibers start condensing, become
shorter and pull chromosomes
(homologues) toward opposite poles.
• It results in the separation and dragging
of recombined homologous
chromosomes towards opposite poles.

6. B. Identify and comment on the stage of Meiosis
Telophase-I
• In this phase chromosomes reach
the opposite poles.
• Nucleolus gets reorganized and
then reappears.
• Nuclear membrane gets
developed around each set of
chromosomes, forming two
daughter nuclei.

7. c. Identify and comment on the technique.
Emasculation -
• Emasculation is done to prevent self
pollination.
• Emasculation is the removal of young
anthers of stamens in the plant selected
female parents, Well be fore anthesis .i.e.
formation of pollen grains.
• Bisexual flower of a plant which is
selected female parent is emasculated.
• Buds are opened and stamens removed
mechanically by forceps are or by giving
hot water treatment.

8. c. Identify and comment on the technique.
Bagging –
• Emasculated flowers are then
bagged in polythene bags or sterile
paper bags to prevent pollination
by undesired pollens. This is called
as bagging.
• The desired pollen grains are
dusted on the mature stigma of
emasculated flower by opening the
bag temporarily.

9. c.Identify and comment on the technique.
Tagging -
• Tag is tied to the bag. The tag
carries brief in information
about the names selected
parent varieties.
• Day, date and time of
emasculation, anthesis and
actual crossing are recorded on
the tag.

10. D. Name the plant and comment on its xeric/ aquatic
adaptation.
Calotropis procera (Rui)
• It is a non succulent xerophyte.
• The leaves are thick and
leathery.
• The plant contains milky latex.

11. D. Name the plant and comment on its xeric/ aquatic
adaptation.
Acacia arabica (Babool)
• It is a non succulent xerophyte
• Leaves are bipinnately compound,
leaflets are very small in size to
reduce transpiration.
• The stipules are modified into
spines to reduce transpiration and
also to protect the plant against
grazing animals.

12. D. Name the plant and comment on its xeric/ aquatic
adaptation.
Opuntia dilleni (Nagphani)
• It is a succulent xerophyte.
• Leaves are modified into spines
to reduce transpiration
• Stem is modified into
phylloclade to perform
photosynthesis and store water.

13. D. Name the plant and comment on its xeric/ aquatic
adaptation.
Hydrilla
• It is a submerged hydrophyte.
• The stem is soft, slender without
mechanical tissue.
• Leaves are arranged in whorls.
Cuticle and stomata are absent.
• The entire plant is covered by
mucilage.

14. D. Name the plant and comment on its xeric/ aquatic
adaptation.
Eichhornia (Water Hyacinth)
• It is a free floating hydrophyte
• Stem is modified into offset, it is
spongy due to aerenchyma.
• The petioles are swollen due to
air chambers.
• Roots are adventitious and have
root pockets.
• Root hair is absent.

15. D. Name the plant and comment on its xeric/ aquatic
adaptation
Typha (Cat tail)
• It is an amphibious anchored
hydrophyte.
• Stem is rhizome with adventitious
roots.
• The leaves are long, linear, soft and
spongy.
• Leaves have mechanical tissue hence
stand erect.
• Cuticle and stomata also present on
the leaves.

16. E. Separation of plant pigments by paper chromatography.
• Aim- To study the separation of plant pigments by paper
chromatography.
• Observation- The chromatography paper strip shows four
different color distinct bands from the loaded spot up to
the top in the following sequence:
i. Yellow green
ii. Blue green
iii. Yellow
iv. Orange
• Conclusion-
The pigments travel at different rates along the
chromatography paper on the basis of their molecular
weight and solubility in the solvent.
 Chloroplast of Spinach leaves contain four different pigments.
• Chlorophyll b- yellowish green
• Chlorophyll a- bluish green
• Xanthophyll- yellow
• Carotene – orange
These four pigments are found in all higher plants.

17. E. Rate of transpiration by four leaf experiment
• Aim- To study the comparative rate of transpiration in upper and lower
surface of leaf by using four leaf experiment.
• Observation-
Sr. no. Type of leaf Observation
1 A looks fresh & green
2 B Slightly dry
3 C Drier than leaf B
4 D Dries completely

18. • Conclusion-
Leaf A: Vaseline is applied on both the
surfaces therefore no transpiration
occurs and leaf is fresh.
Leaf B: Vaseline is applied on lower
surface, so very less transpiration
occurs as number of stomata are less
on upper surface. Therefore the leaf is
slightly dry.
Leaf C: Vaseline is applied on upper
surface so more transpiration occurs
as number of stomata are more on
lower surface. Thus the leaf is more
dry than leaf B
Leaf D: Vaseline is not applied to any
surface. So transpiration occurs from
both surfaces and the leaf dries
completely.

19. F. Identify and describe.
V.S OF ANATROPOUS OVULE:
• It is the most common type of ovule in
Angiosperms.
• Anatropous ovule has bent axis with
micropyle directed downwards.
• It is covered by two integuments
• It consists of embryo sac (female
gametophyte)
• Embryo sac consists of egg apparatus, 2
polar nuclei and 3 antipodal cells.

20. G. Identify the disease causing organism and comment
on the symptoms of the disease caused.
Plasmodium
• Plasmodium causes Malaria
• Symptoms of Malaria include fever,
shivering caused by the release of
hemozoin arthralgia (joint pain),
vomiting, anemia(caused by
hemolysis).
• Cyclic occurrence of sudden coldness
followed by rigor and then fever ,
sweating , lasting for 4 to 6 hours,
occurring every two days.

21. G. Identify the disease causing organism and comment
on the symptoms of the disease caused.
Entamoeba histolytica
• It causes amoebiasis in man.
• Symptoms include amoebic
dysentery, abscess in liver, lungs
& brain.
• Passing out of stool with blood
and mucus
• Abdominal pains, nausea and
bowel irregularity

22. G. Identify the disease causing organism and
comment on the symptoms of the disease caused.
Ascaris -
• The disease caused by Ascaris is
called Ascariasis.
• The common symptom is vague
abdominal pain.
• In severe cases, the patient may
experience restlessness, weight
loss, anorexia, distended abdomen,
intermittent loose stool &
occasional vomiting.

23. G. Identify the disease causing organism and
comment on the symptoms of the disease caused.
Ringworm -
• It is a fungus which infects hair
and feed on keratin.
• It causes dermatomycosis.
• Symptoms of ringworm are red
ring patches lesions on the skin.
• Intense itching and scaly skin.

24. H. Name the part of the brain and mention its function.
CEREBRUM- Largest part of the brain.
• 4 lobes
i. Frontal lobe- controls voluntary
activities , it is related with memory,
intelligence, problem solving,
judgement, reasoning etc.
ii. Parietal lobe- controls sensation of
touch, pressure, pain & temperature.
iii. Temporal lobe- control centers of
smell, hearing & speech.
iv. Occipital lobe- control sense of
vision.

25. H. Name the part of the brain and mention its function.
CEREBELLUM-
• Second largest part of brain.
• Maintains equilibrium, posture,
balancing etc.
• It is center for neuromuscular
activities like walking, running
etc.

26. H. Name the part of the brain and mention its function.
MEDULLA OBLONGATA -
• Controls involuntary vital
functions such as heart beat,
respiration, peristalsis.
• Controls non vital activities such
as coughing, sneezing,
swallowing, vomiting, yawning.

27. I. Identify and describe the permanent slide
T.S of Testis -
• Each testis contains 200-300 seminiferous
tubules.
• Seminiferous tubule is lined by cuboidal
germinal epithelium.
• It shows different stages of
spermatogenesis which are
spermatogonium, primary and secondary
spermatocytes, spermatids and sperms.
• Few large pyramidal cells called
Sertoli/Nurse cells are present interrupting
the germinal epithelium. These provide
nourishment to the sperms till maturation.

28. PERMANENT SLIDE - T.S OF TESTIS

29. I. Identify and describe the permanent slide
T.S of Ovary –
• Internally the ovary shows compact
structure with outer cortex and inner
medulla.
• The medulla shows connective tissue called
stroma. The cortex is lined by germinal
epithelium.
• Different stages of developing ovarian
follicles are seen in the cortex.
• As the follicle grows, it forms secondary
and mature Graafian follicle.
• One ovum from the mature follicle is
released from an ovary in every menstrual
cycle after which mass of yellow cells called
corpus luteum (CL), formed in the cavity of
empty Graafian follicle .If the ovum is not
fertilized, the CL degenerates into a white
body called Corpus Albicans.

30. PERMANENT SLIDE- T.S OF OVARY/ GRAAFIAN FOLLICE

31. I. Identify and describe the permanent slide
V.S of Blastula –
• It shows outermost, small, flattened
cell layer called Trophoblast.
• It encloses a cavity called blastocoel
and an inner cell mass/ embryonal
knob
• The inner cell mass is attached to the
trophoblast on one side. The
trophoblast cells in contact with the
inner cell mass are called cells of
Rauber.

32. PERMANENT SLIDE- V.S OF BLASTULA

33. J. Identify the animal and comment on its xeric/aquatic
adaptation.
CAMEL -
• It is a xerocole animal, adapted to
desert conditions
• It excretes concentrated urine in order
to conserve water.
• It accumulates fat in the hump so that
heat flows away from the body and
inward flow of heat is prevented.
• It has long eye-lashes that protect eye
from sand dunes/ strong winds.

34. J. Identify the animal and comment on its
xeric/aquatic adaptation
KANGAROO RAT –
• It is a xerocole rodent, nocturnal
in habit to avoid heat of the day
and to have humid air inside.
• Kangaroo rat neither sweat nor
pant to keep itself cool.

35. J. Identify the animal and comment on its
xeric/aquatic adaptation
ROHU -
• It is a fresh water fish.
• Body is laterally compressed and
streamlined in order to minimize
resistance of water and thus reduce
friction with water.
• Presence of gills for respiration which
help in exchange of gases in water.
• Body is covered by scales to prevent
osmotic entry of water into the body.

36. J. Identify the animal and comment on its
xeric/aquatic adaptation
DOLPHIN -
• It is an aquatic mammal.
• Body is streamlined, smooth and
furless to reduce friction.
• The position of nostrils near the top
of the head facilitates easy breathing
when animal reaches the surface of
water for breathing.
• Flippers for steering, slowing and
going up & down or out of water.

37. THANK YOU