ANSWERS TO BIO CLASS X SAMPLE PAPER II

1.Light reaction
2.Methane, Carbon dioxide.
3.Cerebellum
4.Benefits of local people by Chipko movement- (i) economic development-The local people became economically developed by trading different forest products without harming the forest. (ii) Social benefit-The forest is a type of shelter for them. Collecting firewood, gums etc became easier for them.(iii)Environmental benefit-Reducing deforestation decreased the pollution of environment and people got a soothing climate.
5.See text book diagram.
6.(a)Organs having same structural plan, same origin, same developmental pattern but differ in function are called homologous organs. E.g. Fore limbs of man & bird. (b)Analogous organs.
7.(i) Released harmful gases cause air pollution. (ii)Gases cause respiratory diseases to man.(iii)cause environmental problems like global warming, acid rain, depletion of ozone layer, smog etc.
8.Glucose is selectively reabsorbed while passing through nephron tubule. Two vital functions of kidney are (i) filtration of nitrogenous waste from blood. (ii) Osmoregulation i.e. keeps balance of water and ions.
9.(a) Trachea does not collapse because it is supported by ‘C’ shaped cartilage. (b) For exchange of gases i.e. oxygen from alveoli moves to capillaries and from capillary blood carbon dioxide moves to alveoli.
10.(a) Sperm, testes, for motility in female reproductive organ, Reproductive gland i.e. prostrate gland. (b) Placenta-Vital connection between mother and fetus .Function- provides necessary material like oxygen, food, antibodies etc to fetus from mother and brings waste from fetus. (c) Release of mature ovum from ovary.

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a) phototrophic, chemotropic, hydrotropic, geotropic (b) Movement of plants or plant parts towards chemicals e.g. movement of pollen tube in ovary. (c) Negative hydrotropism-stem negative phototropism- root (d) mimosa pudica (touch me not) plant.