Question

Motile zygote of Plasmodium occurs in
A.Human RBCs
B.Human liver
C.Gut of female Anopheles
D.Salivary glands of Anopheles

Answer 1

Hint:Plasmodium completes its life cycle in two hosts and two phases: sexual phase in the female Anopheles mosquito host and asexual phase in the human body. The life cycle of Plasmodium vivax is subdivided into three-phase: schizogony, gamogony, and sporogony.

Complete answer: 1.Malaria is a mosquito-borne disease caused by the toxins produced in the human body by the malarial parasite Plasmodium. The malarial parasites are carried from the infected to the healthy person by the female Anopheles mosquito.
2.The life cycle of Plasmodium is divided into the asexual phase in the human body and the sexual phase in the female Anopheles mosquito host.
3.The male and female gametes are sucked up by the female mosquito along with blood. In the stomach of a female Anopheles mosquito, the development of gametocytes takes place which involves gametogenesis (gamete formation) and fertilization (fusion of male and female gametes).
4.The male and female gametes fuse to form ookinete (a fertilized motile zygote), which further develops into new sporozoites that move to the salivary glands of mosquitoes and are ready to infect a new host.
So, the correct answer to the above question is an option (C) i.e. Gut of female Anopheles.

Note: Plasmodium vivax is a parasite that causes malaria in humans. Its life cycle is completed in two hosts: sexual in female Anopheles mosquito and asexual in the human body. The female mosquito sucks up the gametocytes from the human host. These gametocytes then undergo maturation and form a motile zygote in the gut of the female mosquito.