Mammary glands are a defining feature of which class of animals? MCQ with Answer and Explanation

Explanation:
Nitrification is a two-step process: oxidation of ammonia to nitrites by bacteria like Nitrosomonas, and then nitrites to nitrates by Nitrobacter. Ammonification is the release of ammonia from organic matter. Denitrification reduces nitrates to N₂ gas. Nitrogen fixation converts atmospheric N₂ to ammonia. Nitrification makes nitrogen available to plants as nitrates, which are easily absorbed.

Explanation:
During intense exercise, when oxygen supply is insufficient, muscle cells switch to anaerobic glycolysis, producing ATP and lactic acid from glucose. Lactic acid accumulation lowers pH, causing muscle fatigue, soreness, and cramps. It is later converted back to glucose in the liver (Cori cycle). Ethanol is produced by yeast fermentation.

Explanation:
Zinc is a micronutrient (trace mineral) required in small amounts for enzyme function, immune response, and wound healing. Sodium, potassium, and phosphorus are macrominerals.