Arrange the stages in the life cycle of Plasmodium after the bite of mosquito.
(A) gametocytes in human RBCs
(B) sporozoites in mosquito's salivary glands
(C) sporozoites in human liver
(D) Fertilization in gut of mosquito host
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (C), (A), (D), (B)
After a mosquito bite, sporozoites reach the human liver (C); the parasite then multiplies in red blood cells and forms gametocytes in RBCs (A); a mosquito takes up the gametocytes and fertilisation occurs in its gut (D); new sporozoites collect in its salivary glands (B).
NCERT Extract:
Common Diseases in Humans – “… Plasmodium enters the human body as sporozoites (infectious form) through the bite of infected female Anopheles mosquito. The parasites initially multiply within the liver cells and then attack the red blood cells (RBCs) resulting in their rupture. The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. When a female Anopheles mosquito bites an infected person, these parasites enter the mosquito’s body and undergo further development. The parasites multiply within them to form sporozoites that are stored in their salivary glands. When these mosquitoes bite a human, the sporozoites are introduced into his/ her body, thereby initiating the events mentioned above.”