Category: TIFR Previous Year Question Papers 2019 Biology With Answer Key Download

15. Thyroxin is the major hormone produced by the thyroid gland. Rats may be thyroidectomised (THX) either surgically or chemically. In an experiment designed to investigate the relationship of the […]

14. How many bacteria were there in the initial 1 ml sample based on the dilution series shown below? The labels below the tube show the amount of liquid before […]

13. Konopka and Benzer isolated mutant fruit flies that had abnormal daily (circadian) rhythms. The graph below shows the number of fruitflies that eclose each hour of the day (eclosion […]

12. The monoamine serotonin is synthesized mainly by enterochromaffin cells in the intestine. A mouse was treated with broad range of antibiotics for a week. After a week, both the […]

11. The poison dart frog, or poison arrow frog in the family Dendrobatidae carry Batrachotoxin, among other agents. The toxin irreversibly binds to voltage-gated sodium channels and keeps them open. […]

10. Which one of the following cannot form a bilayer by itself? a. Glycerophospholipids b. Cholesterol c. Phosphatidic acid d. Glycerolipids Cholesterol cannot form a bilayer by itself. This makes it […]

9. Human red blood cells (RBCs) cannot be grown in cultures because a. RBCs require a steady oxygen supply b. RBCs are extremely fragile c. RBCs are terminally differentiated cells […]

8. Galvani discovered in the 1700s that frog’s legs jerked when touched with a piece of copper and a piece of iron, simultaneously. This happens because action potentials are triggered […]

7. Of the graphs shown below, which is most representative of the kinetics of ion transport through a membrane channel? a. Graph (A) b. Graph (B) c. Graph (C) d. […]

6. In an experiment, two fly populations are separately maintained for many generations. Population A contains closely-related individuals. Population B contains a set of unrelated individuals. Over many generations it […]