Question

Describe the asexual and sexual phase of life cycle of Plasmodium that causes malaria in humans.

Answer 1

Hint: Malaria is caused by the toxins produced in the human body by the parasite Plasmodium. It is transmitted from an infected person to the healthy person by the action of Anopheles mosquito.

Complete answer:
The two phases i.e asexual reproduction occurs in the human host whereas the sexual phase pccurs in the female Anopheles mosquito. The phases are described below-
Asexual phase:- It occurs inside the human body. The toxins released by the parasite is known as sporozite. These sporozite enter the liver cells and start dividing to give rise to merozoites, which are then released into the bloodstream. These merozoites move towards the red blood cells. After invading red blood cells they first form a signet ring stage followed by the amoeboid stage and ultimately leads to the rupture of Red blood cells causing a cycle of fever along with chills. Merozoites released from the ruptured Red blood cells, some of them further target the other red blood corpuscle and form male gametophyte and female gametophyte i.e sexual stages in red blood cells.
Sexual phase:- The female mosquito takes up gametocytes along with the blood meal. Fertilisation occurs followed by the development in the mosquito stomach. Mature sporozoites are the infective stages that escape from the intestine and move towards the mosquito's salivary gland.

Note:
Plasmodium completes its life cycle in two hosts i.e primary host is mosquito itself and secondary host is man. When the infected mosquito bites a healthy human being then the parasites migrate into his blood with the saliva.