12th Biology Practical Spotting Q.4.pptx

Its is useful for studying the experiments and practical uses

1. B i o l o g y P r a c t i c a l P a r t B Q . N o . 4 S p o t t i n g S t d : - 1 2 t h 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 called lever mechanism . 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: Yellow green Blue green Yellow 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. C onclusion - 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 Frontal lobe - controls voluntary activities , it is related with memory, intelligence, problem solving, judgement, reasoning etc. Parietal lobe - controls sensation of touch, pressure, pain & temperature. Temporal lobe - control centers of smell, hearing & speech. 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.

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