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 ?

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]

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]

What environmental problems can originate if the concentration of different greenhouse gases polluting air increases in a steady manner?

Prepare a list of reactants used and products in the experiment of Miller and Urey regarding biochemical origin of life.

What advantages did Mendel enjoy owing to pea-flowers being bisexual and self pollinating?

With the help of an example explain how the phenotypic and genotypic ratios found in F2 generation of certain hybrid crosses indicate exception to Mendel's first law of heredity.

What are the roles of Insulin hormone regarding the following two aspects related with metabolism of carbohydrates? Breakdown of glucose Transformation of glucose

If the detergent rich in ____ used for washing human clothes gets mixed in a pool, it results in eutrophication.

Which of the following is an inference of Darwin's theory of evolution? (a) Natural Selection (b) Variation (c) Prodigality of reproduction (d) Food and Space is constant

What is the numerical ratio of the four genotypes BBRR, BBrr, bbRR and bbrr produced in the F2-generation resulting from dihybrid cross in Guinea pig? (a) 1 : 1 : 1 : 1 (b) 2 : 4 : 2 : 4 (c) 4 : 2 : 2 : 1 (d) 2 : 4 : 1 : 2

Which of the following events occurs during sexual reproduction of flowering plants? (a) Zygote is converted into fruit (b) Zygote is converted into seed (c) Unicellular zygote is converted into multicellular embryo (d) Ovary is converted into embryo