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

Explanation

Malaria: It is a protozoan, disease, caused by various species of Plasmodium such as.P. malariae P. vivax and P. falciparum. These species cause different types of malaria.
For the completion of life cycle Plasmodium requires two hosts (i) Human (») Mosquitoes. Female Anopheles mosquito acts as the vector (an organism which spreads the pathogens).
Life cycle of Plasmodium involves :
(A) Asexual Phase in Man.
(i) Sporozoites enter the human body through the bite of infected female Anopheles mosquito, a vector transmitting the disease.
(ii) From the blood, they enter liver cells and multiply within the liver cells.
(iii) Infected liver cells burst, and release the parasites again in the blood.
(iv) They attack RBCs repeatedly, multiply and cause their rupture.
(v) Ruptured RBCs release a toxin called haemozoin which is responsible for high recurring fever and resultantly the chill/shivering.
(B) Sexual Phase in Mosquito.
(i) When a female Anopheles mosquito bites an infected person, these parasites as male and female gametocytes enter the mosquito body and undergo further development.
(ii) Parasites multiply in this stomach wall of the mosquito and again Sporozoites which are stored in salivary glands and are transferred to a human body during bite of the mosquito.