The scientist who discovered the structure of chlorophyll was: MCQ with Answer and Explanation

Explanation:
Helicobacter pylori colonizes the gastric mucosa, causing chronic inflammation, peptic ulcers, and increasing the risk of gastric cancer. It survives stomach acid by secreting urease, which converts urea to ammonia, neutralizing acid. Treatment involves antibiotics and acid suppressants.

Explanation:
Leptin is a peptide hormone produced primarily by adipocytes (fat cells). Its concentration in the blood is proportional to the amount of body fat. Leptin acts as a satiety signal, crossing the blood-brain barrier to act on receptors in the hypothalamus. It suppresses appetite (anorexigenic effect) and increases energy expenditure, thereby regulating long-term food intake and body weight. It is often called the 'satiety hormone' or 'fat hormone'.

Explanation:
Spectrin is a cytoskeletal protein that lines the inner surface of the RBC membrane, maintaining its biconcave shape and providing elasticity to squeeze through capillaries. Hemoglobin carries oxygen, myosin is a motor protein, keratin is structural in skin/hair. Defects in spectrin cause spherocytosis.