Consider statements about human diseases: 1. Common cold is caused by a virus. 2. Typhoid is transmitted through contaminated food and water. 3. Plague is transmitted by the bite of a rat flea. Which are correct? MCQ with Answer and Explanation

Explanation:
Glycogen is a highly branched polysaccharide of glucose, often referred to as 'animal starch'. It is the primary storage form of carbohydrates in animals and fungi. It is mainly stored in the liver and muscle cells. When blood glucose levels drop, glycogen is broken down (glycogenolysis) to release glucose for energy.

Explanation:
Pepsin is the primary proteolytic enzyme in the stomach, breaking down proteins into peptones. Trypsin is a pancreatic enzyme secreted by the pancreas, not the liver, which continues protein digestion in the small intestine. Bile, produced by the liver, emulsifies fats, but lipase (pancreatic lipase) actually digests (hydrolyzes) them into fatty acids and glycerol. Only statement 1 is correct.

Explanation:
Genetic drift is the random fluctuation of allele frequencies in a population, particularly significant in small populations, due to chance events. Gene flow (migration) is the transfer of alleles from one population to another through the movement of individuals or gametes. Natural selection is a non-random, deterministic process where individuals with traits better suited to their environment have higher survival and reproductive success. Thus, statements 1 and 2 are correct.