PUC CLASS 12 PRACTICAL VIVA -VOCE .

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Prepare a temporary slide of given material "A" by taking a transverse section of ovary ar report the number of locules and type of placentation
EXERCISE — 1
Q.1) What is meant by pentalocular ovary? Ans: An ovary with five locules (chambers).
Q.2) What is Placentation? Ans: Arrangement of ovules on the placenta
Q.3) What is meant by multilocular ovary? Ans: Ovary having many locules (Hibiscus, Lady's finger)
Q.4) What is a locule? Ans: Locules are chambers within the ovary containing ovules.
Q.5) How many ovules are present in each locule of Hibiscus? Ans: Two.
Q.6) What is axile placentation? Ans: Ovules attached to the central placenta.
Q.7) How many locules can be observed in the T.S of Hibiscus ovary? Ans: Five locules (Pentalocular).
Q.8) What is the type of placentation observed in the Hibiscus ovary? Ans: Axile placentation.

Prepare a temporary slide to show pollen germination from the given material "A" and calculate the percentage of Pollen germination

EXERCISE — 2  

Q.1) Which nutrient solution is used to induce pollen germination? Ans: 10% sucrose solution or 10% sucrose solution containing Boric acid and Calcium nitrate. 

Q.2) What is a germ pore? Ans: A pore or an opening on exine wall through which pollen tube emerges out. 

Q.3) Name the part of the pollen grain through which pollen tube emerges out. Ans: Germ pore. 

Q.4) Where do the pollen grains germinate on the flower? Ans: On the Stigma. 

Q.5) What is intine? Ans: The inner wall of pollen grain. 

Q.6) What is exine? Ans: The outer wall of pollen grains. 

Q.7) What does pollen tube carry? Ans: The pollen tube carries the male gametes. 

Q.8) What is the formula used to calculate percentage of pollen grain germination? Ans: n x 100/N where, n= Number of germinated pollen grains N= Number of pollen grains in a field of microscope. 

Prepare a temporary slide to show pollen tube growth on the stigma from the given materia "A" and draw a labeled diagram .

EXERCISE — 3

Q.1) Through which tissue does the pollen tube pass to reach the ovule? Ans: The stylar tissue. 

Q.2) Which stain is used to observe growth of pollen tube? Ans: Cotton blue 

Prepare a temporary slide — "A" nuclear staining EXERCISE —13  Q.1) Name the nuclear stain used in temporary slide preparation of onion epidermal peel. Ans: Acetocarmine / Acetoorcein.
Q.2) Why does the nucleus get darkly stained to acetocarmine? Ans: Nucleus is rich in nucleic acids which combine with Acetocarmine to from a deep red conjugate. Hence nucleus appears to be darkly stained.
Q.4) Why the acetocarmine is used for nuclear staining? Ans: Acetocarmine has the ability to bind to nucleic acids. Since nucleus is rich in nucleic acids, acetocarmine is used to stain nucleus.
Q.5) What is the shape of the cell observed in the onion epidermal peel? Ans: Rectangular.
Q.6) How many nuclei can be observed in onion epidermal cell? Ans: A single nucleus.
Q.7) Name the monomer unit of nucleic acids. Ans: Nucleotide.
Q.8) Which part of the cell gets stained with acetocarmine? Ans: Nucleus.
Prepare a temporary slide of "B" — Mitotic study

 EXERCISE — 6 

Q.1) Why mitosis is called equational division? Ans: The chromosome number remains the same to that of parent cell.
Q.2) Name the first phase of cell division? Ans. Prophase
Q.3) What is Karyokinesis? Ans: Division of the nucleus.
Q.4) What is Cytokinesis? Ans: Division of the cytoplasm.
0.5) Mention the phase of cell division during which the separation of chromatids take place. Ans: Anaphase.
Q.6) Mention any one feature of Prophase. Ans: Disintegration of nuclear envelope/ disintegration of nucleolus / condensation of Chromatin.
Q.7) In which stage of mitosis, chromosomes are arranged on the equatorial plate? Ans: Metaphase.
Q.8) During which phase of mitosis chromosomes assume V, L, J and I-shapes? Ans: Anaphase.
Q.9) In which stage of mitosis, the nuclear envelope and nucleolus reappears? Ans: End of Telophase
Q.10) What is the characteristic feature of metaphase? Ans: Chromosomes are arranged in equatorial plane.
Q.11) In which stage of mitosis splitting of centromere occurs? Ans: Early anaphase.
Q.12) How does cytokinesis happen in plant cells? Ans: In plant cells, a cell plate is formed in the middle after/during telophase which cuts the cell into two.
Conduct a suitable test for soil & water samples Cl and C2 and report the pH values.

EXERCISE — 19

Q.1) What is the range of acidic pH? Ans: 1-7
Q.2) What is the range of basic pH? Ans: 7-14.
Q.3) What is the value of neutral pH? Ans: 7
Q.4) What do you mean by broad range pH? Ans: pH whose range is from 1 to 14.
Q,5) What do you mean by narrow range pH? Ans: pH whose range is from 6.5 to 9.
 Q.6) What component of soil or water determines the pH? Ans: Hydrogen ion concentration. 

Identification and comment on "D" EXERCISE — 4  T.S of Testis Q.1) Mention any one cell type seen in the T.S. of mammalian testis. Ans: Spermatogonial cells / Spermatocytes / Spermatids / Spermatozoa/ Sertoli cells/Leydig cell 

Q.2) Where do you find interstitial cells in the testis? Ans: In the stroma between seminiferous tubules. 

Q.3) To which cells of the seminiferous tubule the spermatozoa are attached? Ans: Sertoli cells. 

Q.4) Name the cells present in the testis that secrete testosterone. Ans: Leydig cells or Interstitial cells. 

Q.5) What are spermatogonia? Ans: The cells that undergo spermatogenesis. 

Q.6) What are Sertoli cells? Ans: Nutritive cells present in the seminiferous tubules / Cells of seminiferous tubule that nourishes the developing spermatozoa. 

Q.7) Name the male Gonad. Ans. Testis 

T.S. of Ovary 

Q.1) Name the structural component associated with oogenesis present in the Ovary. Ans: Ovarian follicle. 

Q.2) Name the cavity present in the Graafian follicle. Ans: Antrum. 

Q.3) Name the fluid present in the antrum of the Graafian follicle. Ans: Liquor folliculi. 

Q.4) What is the female gonad called? Ans: Ovary 

Q.5) What is corpus albicans? Ans: Degenerated corpus luteum is called corpus albicans. 

Female gametophyte development in the ovary of a flower — Q.4 — "D" 

EXERCISE — 5  

Q,1) How many cells and nuclei are present in the female gametophyte of a flower? Ans: 7 cells and 8 nuclei. Q.2) Expand PEN Ans: Primary Endosperm Nucleus Q.3) Name the two poles of the embryo sac. Ans: Micropylar end and Chalazal end. 

Q.4) What are Integuments? Ans: The external protective layers of embryo sac. Q.5) Name the cells in the embryo sac having polar nuclei. Ans: Central cell. 

0.6) Name the stalk of the ovule. Ans: Funiculus. 

Q.7) Towards which end of the embryo sac, the egg apparatus is found? Ans: Micropylar end. 

Q.8) How many antipodals are present at the Chalazal end? Ans: Three 

T.S of Mammalian Blastula — Q.4 — "D" 

EXERCISE — 8 

 0.1) Name the cavity present in the blastocyst. Ans: Blastocoel. 

Q.2) Mention any one cell type present in the blastocyst. Ans: Trophoblast / inner cell mass Q.3) What are cells of Rauber? Ans: The trophoblast cells that cover over the inner cell mass. 

Q.4) What is blastocoel? Ans: Blastocoel is the fluid filled cavity present in the blastula. 

Q.5) What is trophoblast? Ans: The outer most layer of cells of the blastocyst.

 Q.6) Which cell of mammalian blastula develop into embryo proper? Ans: Inner cell mass. 

Study of meiosis — Q.4 — "D" EXERCISE — 7  

Q.1) Name the sub-stages of prophase-I in correct order. Ans: Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis. 

Q.2) At what sub-stage Prophase-I chromosomes are observed as bivalents? Ans: Zygotene. 

Q.3) Which sub-stage of prophase-I is called tetrad stage? Ans: Pachytene stage. 

Q.3) Name the sub-stage of prophase-I in meiosis during which the chiasmata can be observe for the first time. Ans: Diplotene. 

Q.4) At which phase of meiosis, the homologous pair of chromosomes are separated? Ans: Anaphase-I 

Q.5) At which phase of Meiosis the replicated chromosomes are separated by the splitting centromere? Ans: Anaphase -II 

Q.6) At which sub-stage of Prophase-1 pairing of homologous chromosome occur? Ans: Zygotene. 

Q.7) At the end of Meiosis how many daughter cell are produced? Ans: Four. 

Q.8) In which organs of our body meiosis takes place? Ans: Gonads (Testis and Ovary) 

Identification and commenting on the disease causing organism "E" 

EXERCISE — 14 

Q.1) Name the causative organism for Malaria. Ans: Plasmodium vivax 

Q.2) To which Protozoan class Entamoeba belongs to? Ans: Rhizopoda / Sarcodina 

Q.3) To which Protozoan class the Plasmodium belongs to? Ans: Sporozoa. 

Q.4) Mention the insect host of Plasmodium. Ans: Female Anopheles mosquito. 

Q.5) Name the class to which Ascaris is included. Ans: Nematoda. 

Q.6) Give the scientific name of Roundworm. Ans: Ascaris. 

Q.7) Mention any one symptom of malarial fever? Ans: High fever / Chills / Sweating 

Q.8) Mention any one symptoms of Ascariasis. Ans: Irregular bowel / Occasional vomiting / anaemia. Q.9) Mention any one symptom of Ringworm disease. Ans: Infected area of skin is itchy / red / with scaly patches giving ring like appearance. 

Q.10) Name the organism that causes Ascariasis. Ans: Ascaris lumbricoides. 

Q.11) Name the organism that causes amoebic dysentery. Ans: Entamoeba histolytica. 

Identification and commenting of "F" EXERCISE — 17  Xeric and Hydric adaptations — Plants 

Q.1) Mention any one xeric adaptation found in Opuntia. Ans: Green and fleshy stem / Leaves modified into spines. 

Q.2) Mention any one adaptation in xeric plants for prevention of loss of water by transpiration Ans: Sunken stomata / Modification of leaves as spines or scales/ Thick cuticle on leaf surface. 

Q.3) What type of leaves are seen in Pinus / Casuarina. Ans: Needle like leaves. 

Q.5) Name the tissue present in aquatic plants that provides buoyancy. Ans: Aerenchyma 

Q.7) What is the function of aerenchyma in hydrophytes? Ans: Buoyancy. 

Identification of xeric and hydric adaptation "F" EXERCISE — 18  Xeric & Hydric adaptations — Animals 

Q.1) Mention any one aquatic adaptation found in frog. Ans: Webbed toes help in swimming / Mucous glands for cutaneous respiration / Nictitating membrane for protection of eye in water. 

Q,2) Mention any one aquatic adaptation of fishes. Ans: Fins — swimming and balancing/ Gills — respiration /Stream-lined body to cut water currents / Scales for protection/ 

Q.3) Name any one aquatic adaptations found in prawn. Ans: Chitinous exoskeleton for protection / Gills for respiration / Uropod for changing direction. 

Q.4) What is the significance of nictitating membrane in frog? Ans: Protection of eye in water. 

Q.5) Mention any one xeric adaptation found in camel. Ans: Padded foot for walking in sand / Hump for storage of fat / Eyes with long eye lashes. 

Q.7) Mention one adaptations of rat for xeric conditions. Ans: They prefer juices as food and consume very little water / As they live in burrows underneath, they have well developed ear pinna for sound perception. 

Q.8) Mention any one xeric adaptations found in squirrels. Ans: Hair on the body for protection and avoidance of evaporation. 

Identification and Comment on "F" 

EXERCISE — 25 

Homologous and Analogous organs 

Q.1) What are homologous organs? Ans: Organs that have similar structure and origin but different function. 

Q.2) What are analogous organs? Ans: Organs that have different structure and origin but similar function. 

Q.3) Why are scale leaves of Onion and spines of Opuntia called homologous organ? Ans: They are similar in origin but perform different functions. Scale leaves of Onion store food while the spines of Opuntia provide protection. 

Q.4) What type of organs, the tendrils of Balloon vine and bulbils of Agave are? Ans: Homologous organs. 

Q.5) Why are Tendrils of Vitis and thorns of Carissa called homologous organs? Ans: Both have similar origin but tendrils of Vitis helps in anchorage while the thorns of Carissa are defensive in function. 

Q.6) Why the stem tendrils and leaf tendrils are called analogous organs? Ans: They have different origin but perform same functions, namely, anchorage. 

Q.7) In Vitis which part is modified into a tendril. Ans: Terminal bud. 

Q.8) In Pea plant which part is modified into tendril? Ans: Leaves. 

Q.9) What is the function of modified stems like rhizome, tuber and corm? Ans: Storage / Vegetative Propagation. 

0.10) What is the function of modified roots like Carrot/Radish/ Beetroot? Ans: Storage of food. Q.11) Why are forelimbs of bats and human beings are called homologous organs? Ans: They are similar in origin but perform different function. In bats, the forelimbs help in flight while in Human, used for various non-locomotory activities. 

Q.12) Why the wings of insect and wings of bird are called analogous organs? Ans: They have different origin but perform same function. The wing of an insect is supported by chitinous exoskeleton. The wing of bird is supported by fore limb skeleton and is covered with feathers. 

Q.13) What the type of organs the mandible of cockroach and mandible of vertebrate are? Ans: Analogous organs.