Question

the gametocytes of the malaria - causing organism plasmodium develop into merozoites. give rise to zygotes within the mammalian circulatory system. are picked up by a feeding mosquito from the human hosts blood. inhabit the salivary glands of anopheles mosquitoes. are the infective stage obtained from the insect vector.

Explanation:

Gametocytes of Plasmodium in human blood are ingested by a feeding Anopheles mosquito. They do not develop into merozoites (merozoites come from sporozoite - liver cell - schizont pathway), zygotes form in the mosquito's gut not in the mammalian circulatory system, they don't inhabit mosquito salivary glands (sporozoites do), and they are not the infective stage from the insect vector (sporozoites are).

Answer:

are picked up by a feeding mosquito from the human host's blood.