What does ICZN stand for in biological nomenclature? MCQ with Answer and Explanation

Explanation:
Hemoglobin in red blood cells binds oxygen in the lungs and releases it in tissues. Each hemoglobin molecule can bind four O₂ molecules. It also carries some CO₂.

Explanation:
Ingestion is the act of taking food and liquids into the body through the mouth. Digestion is the breakdown, absorption is nutrient uptake, egestion is waste elimination. Ingestion is the first step in nutrition.

Explanation:
The corpus luteum, formed after ovulation, secretes progesterone (and some estrogen) to maintain the uterine lining for pregnancy. If no fertilization, it degenerates, causing menstruation. Estrogen is also produced by growing follicles, testosterone by Leydig cells, prolactin by anterior pituitary.