Vegetative organs indicate convergent evolution.

What information related to evolution can be obtained from the discussion on comparative structure of hearts of different vertebrate groups ? Explain the following two terms in the light of Darwinism - (a) Survival of the fittest (b) Natural selection OR Explain the evolutionary significance of homologous and analogous organs with the help of example. What are the adaptive significances of air sacs of Pigeon ? [3+2=5]

What types of struggle for existence can be found among the animals of a forest over eating meat of a freshly killed prey?

What is the adaptive feature of Camel related to its ability to withstand extreme water loss? (a) Cylindrical Red Blood Corpuscle (b) Circular Red Blood Corpuscle (c) Oval Red Blood Corpuscle (d) Cuboidal Red Blood Corpuscle

Explain the theory of Darwin with regard to the lengthening of the neck of a giraffe. What do you mean by 'Hot Dilute Soup'? [3+2=5] OR Construct the sequence of major events of organic evolution with the help of a schematic diagram. Give two examples of the problem-solving ability of chimpanzees. [3+2=5]

Write three inferences deduced from the observations as mentioned in Darwin’s theory of origin of new species by natural selection with the help of a table. Explain the problem-solving ability of Chimpanzee regarding procurement of food. [3 + 2]

Show the major events of evolution with the help of a chart. What are the roles of air sacs in the flight of pigeon? [3 + 2]

Establish the relationship between the ability to withstand extreme water loss and the shape of RBC in Camel.

One of the environmental problems of Sunderbans is imbalance in prey - predator number — Justify the validity of the statement with three examples. What are the roles of biosphere reserve and sanctuary in the conservation of biodiversity ? [3+2=5] OR What are the causes for the endangeredness of the following wild animals ? [3+2=5] Royal Bengal Tiger One-horned Rhinoceros Lion What are the two effects of air pollution on human health ?

Explain the following three problems related to ever-increasing human population- Over-exploitation and depletion of natural resourcese Changes in atmospheric condition and global warming Deforestation and loss of ecosystems Two major causes behind the loss of biodiversity are over-exploitation and destruction of habitat due to change in land use pattern - establish the validity of the statement with proper example. [3+2=5] Or What might be the reasons behind the disturbances in Nitrogen Cycle ? It is very much essential to publish a PBR document for each village of India — which information can be gathered from a PBR regarding biodiversity ? [3+2=5]

Write the name of the chemical constituents of eukaryotic chromosome with the help of a table. What happens to a cell when the cell loses control at different points in cell cycle on division ? [3+2=5] OR What events occur during Anaphase stage of mitotic cell division ?Show the steps of sexual reproduction of flowering plants with the help of word diagram. [3+2=5]

Write one function each of the following five parts of a neuron: [1×5=5] (a) Dendron (b) Axon (c) Myelin Sheath (d) Schwann Cell (e) Node of Ranvier Or Write one function each of the following five parts of an eukaryotic chromosome: [1×5=5] (a) Chromatid (b) Centromere (c) Nucleolar Organizer (d) Satellite (e) Telomere