Diversity of Chordates — DU B.Sc. (Hons.) Zoology Previous Year Question Papers

2. Attempt five questions in all. 4. Draw well labelled diagrams wherever required. (a) Define each of the following terms: -3) (iii) Retrogressive metamorphosis (b) Differentiate between each of the following: (i) Notochord and Stomochord (3x2=6) (ii) Anura and Urodela (iii) Poikilotherms and Homeotherms (c) Give the location and function: of each of the following : (i) Chloride cells (iii) Endostyle 2. (a) Discuss the echinoderm theory of origin of chordates. (8) (b) Give an account of the general characteristics of cephalochordates. (7) 3. (a) Discuss parental care in amphibians by citing examples in support of your answer from all the orders that you have studied. (8) (b) How do freshwater fishes maintain an internal balance of salt and water? (7) 4. (a) Discuss in detail the biting mechanism of venomous snakes. (10) (b) Briefly describe latitudinal migration in birds. (5) 5. (a) Give a detailed account of Wegener's hypothesis for distribution of animals on earth. How does it correlate with the geological time scale? (10) (b) Add a note on plate tectonics. (5) Write short notes on any three of the following (a) Characteristics of mammals (b) Tornaria larva (c) Ethiopian realm (d) Functions of swim bladder in fishes