Question

Intermediate host of malarial parasite is
(a)Pig
(b)Man
(c)Mosquito
(d)Larva of mosquito

Answer 1

Hint: They are the best-known vectors which are responsible for the transmission of human malaria and other diseases in endemic areas. The body of these vectors is dark brown to black in color and divided into three sections: head, thorax, and abdomen.

Complete answer:
The intermediate host of malarial parasites is a mosquito of the genus anopheles that can infect humans and other mammals. Malaria is caused by mainly the protozoan parasite Plasmodium. In humans, malaria is caused by four various species of Plasmodium such as P. falciparum, P. malariae, P. ovale, and P. vivax.

The life cycle of plasmodium:
- The malarial parasite life cycle includes two hosts, one is a vertebrate host like humans and the others are blood-feeding insects.
- Parasites are generally introduced into the human body during a blood meal by female Anopheles mosquito in the form of sporozoites.
- These sporozoites rapidly pass to the liver cells and multiply asexually for 7-10 days without causing any symptoms.
- These parasites are released from the liver in the form of merozoites and enter into the bloodstream.
-In the bloodstream, merozoites attack RBCs and multiply again inside it until the cell rupture.
- Blood stage parasites are responsible for the fever in patients.
- Some of the infected blood cells merozoites mature into sexual forms of the parasite, called gametocytes, that circulate in the bloodstream.
- When an Anopheles mosquito bites an infected human, it ingests the gametocytes that further develop into mature sex cells called gametes.
- After fertilization, these gametes develop into moving ookinetes that finally form the oocyte in the exterior surface.
- This oocyte develops thousands of sporozoites. These sporozoites release into the body when oocyte rupture and travel to the mosquito’s salivary glands.
- The cycle of infection begins again when mosquitoes bite another person.

So, the correct answer is ‘Mosquito’.

Note:
-Culex mosquitoes host the Plasmodium species that cause malaria in birds.
-The important vectors of Plasmodium vivax involve Anopheles sundaicus and Anopheles subpictus.
-Plasmodium is unicellular eukaryotes that are obligate parasites of vertebrates and insects