Which of the following statements about the human reproductive system is correct? MCQ with Answer and Explanation

Explanation:
Folic acid (vitamin B₉) is reduced to tetrahydrofolate (THF), which carries one-carbon groups in amino acid and nucleotide metabolism. Biotin is for carboxylation, riboflavin for redox, thiamine for decarboxylation.

Explanation:
Ginger is a rhizome, an underground modified stem growing horizontally, bearing nodes, internodes, scale leaves, and buds. Potato is a tuber, gladiolus a corm, onion a bulb (modified stem with fleshy leaf bases). Rhizomes store food and aid vegetative propagation.

Explanation:
Prolactin, from the anterior pituitary, promotes mammary gland development and milk synthesis. Oxytocin triggers milk ejection. Estrogen and progesterone prepare breasts during pregnancy but inhibit milk secretion.