Consider statements about vitamins: 1. Vitamin B12 contains cobalt. 2. Vitamin K is essential for blood clotting. 3. Beriberi is caused by Vitamin C deficiency. Which are correct? MCQ with Answer and Explanation

Explanation:
Glycogen is a highly branched polysaccharide of glucose, the storage form in animals, found mainly in the liver and skeletal muscles. Starch is the plant equivalent. Cellulose is structural in plants, sucrose is a disaccharide. Glycogen can be rapidly mobilized to maintain blood glucose.

Explanation:
The left ventricle has the thickest and most muscular wall of all the heart chambers. This is because it must pump oxygenated blood with high pressure through the aorta to supply the entire systemic circulation of the body. The right ventricle only pumps blood to the lungs, which requires much less pressure.

Explanation:
The pineal gland, a small endocrine gland located in the epithalamus of the brain, is often called the 'biological clock' or the 'third eye' in some lower vertebrates. Its primary function in humans is to secrete the hormone melatonin. Melatonin production is regulated by the light-dark cycle (circadian rhythm); it is produced in higher amounts during the night and suppressed by light. Melatonin helps regulate sleep-wake cycles, seasonal reproductive functions, and metabolism.