The organ that produces the hormone erythropoietin is the: MCQ with Answer and Explanation

Explanation:
Villi are microscopic finger-like projections on the inner lining of the small intestine, covered with microvilli (brush border), greatly increasing surface area for absorption of digested nutrients. Each villus contains a lacteal (lymph capillary) and blood capillaries. Alveoli are in lungs, nephrons in kidneys, cilia are hair-like projections on cells.

Explanation:
Chlorophyll a is the primary photosynthetic pigment that acts as the reaction center in photosystem I (P700) and II (P680), converting light energy to chemical energy. Accessory pigments like chlorophyll b, carotenes, and xanthophylls absorb light and transfer energy to chlorophyll a. Phytochrome is involved in photoperiodism. Without chlorophyll a, photosynthesis cannot occur.

Explanation:
The sperm cell is the smallest cell in the human body, about 5 µm in length (head). The ovum is the largest (about 100 µm diameter). RBCs are about 7-8 µm, neurons can be up to a meter long. Sperm cells are highly specialized for motility and genetic material delivery.