The hormone that promotes the development of male secondary sexual characteristics is:
A. Progesterone
B. Prolactin
C. Estrogen
D. Testosterone
Answer: Option D
Solution (By JKExamLibrary)
Testosterone, secreted by Leydig cells of the testes, is responsible for the development of male secondary sexual characteristics like facial hair, deepening of voice, and muscle growth. Estrogen and progesterone are female hormones.
Explanation:
Passive diffusion is the net movement of molecules down their concentration gradient without energy. Osmosis is water diffusion, active transport uses energy, endocytosis is vesicular uptake.
Explanation:
Basophils, and similarly mast cells in tissues, release histamine and other inflammatory mediators during allergic and hypersensitivity reactions. Neutrophils are first responders to infection, lymphocytes are adaptive immune cells, monocytes become macrophages. Histamine causes vasodilation and bronchoconstriction.
Explanation:
The pollen tube typically enters the ovule through the micropyle, a small opening in the integuments. This is called porogamy. Occasionally, entry through the chalaza (chalazogamy) or integuments (mesogamy) occurs. The micropyle also allows water entry during seed germination.
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