Assertion (A): Fermentation produces less ATP than aerobic respiration. Reason (R): Fermentation involves only glycolysis and does not use the Krebs cycle or electron transport chain. MCQ with Answer and Explanation

Explanation:
During metaphase, chromosomes are maximally condensed and align at the cell equator (metaphase plate) attached to spindle fibers via kinetochores. This alignment ensures equal segregation. In prophase, chromosomes condense; anaphase, sister chromatids separate; telophase, nuclear envelope reforms. Metaphase is the best stage for studying chromosome morphology for karyotyping.

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:
Carbohydrates are the body's primary and most efficient source of energy, broken down into glucose to fuel cellular activities. Proteins are essential macronutrients composed of amino acids, crucial for the growth, maintenance, and repair of body tissues, as well as forming enzymes and hormones. Fats are essential for numerous bodily functions, including providing concentrated energy, forming cell membranes, insulating the body, and absorbing fat-soluble vitamins. Thus, statements 1 and 2 are correct.