Introduction to Biology — DU B.Sc. (Hons.) Zoology Previous Year Question Papers

(a) Differentiate betwen the following (any two) : 2x2=4 (i) Animal cell and Plant cell (b) Fill in the blanks : 1×5=5 (i) Lactose consists of ..... joined to .............. by a B-1, 4-glycosidic linkage. (i) (ii) Oleic acid is an unsaturated fatty acid. During cytokinesis, a cleavage furrow is not formed in a plant cell. (iii) Fructose is an aldose sugar. (d) Define the following (any three) : (i) RNA The bonds that link amino acids are called ...................... bonds. (iii) Breeding an organism of unknown genotype with recessive homozygote is called a ...................... because it can reveal the genotype of that organism. (iv) The ...................... is known as the kitchen of the cell. (c) True or False : 1×3=3 (a) (iii) Ecosystem (iv) Biological species concept. Differentiate between mitosis and meiosis. Describe the various phases of a somatic cell cycle in an animal cell. 3+7=10 (b) Explain codominance with a suitable example. 5 (a) Define the term reproductive isolation. Explain the various prezygotic barriers with suitable examples. 1+9=10 (b) Write a note on Miller-Urey experiment. 5 4. (a) Describe Watson and Crick model of DNA. 9 (b) Write about double membrane organelles found in an animal cell (any two). 6 5. 6. (a) Discuss the storage and structural properties of polysaccharides, giving one example of each. 6 (b) Define the term model organism. Give suitable examples and explain why we use model organisms in research. Write short notes on the following (any three) : (a) Incomplete dominance (b) Key events in the history of life (c) Functions of proteins (d) Domain Archaea (e) Natural selection.