Which of the following is a correct statement about a typical bacterium? MCQ with Answer and Explanation

Explanation:
Photosynthesis is the anabolic process in which plants, algae, and cyanobacteria convert CO₂ and H₂O into glucose and O₂ using light energy, catalyzed by chlorophyll. Respiration breaks down glucose to release energy, fermentation is anaerobic breakdown, chemosynthesis uses chemical energy (in some bacteria).

Explanation:
Vitamin D (cholecalciferol) is unique as it can be synthesized in the skin from 7-dehydrocholesterol in the presence of UV-B radiation. It acts as a hormone to regulate calcium and phosphate homeostasis. It must be activated in the liver and kidneys. It is also obtained from dietary sources like fatty fish, egg yolk. Deficiency causes rickets/osteomalacia.

Explanation:
Galanin is a 29-amino acid neuropeptide that is co-localized with several other neurotransmitters and hormones. In the central nervous system, it is involved in various functions, including the inhibition of acetylcholine release and modulation of pain. In the gastrointestinal tract and pancreas, its primary functions are inhibitory: it inhibits the release of both insulin and glucagon from the pancreatic islets, inhibits gastric emptying and gastric acid secretion, and generally inhibits intestinal motility and secretion. It acts to slow down digestion and nutrient absorption.