In the life cycle of Plasmodium, the gametocytes develop in

The correct answer is Option (2) → RBC of human host

Plasmodium passes its life in two hosts. In the human it multiplies asexually; in the female Anopheles mosquito it reproduces sexually. Gametocytes are the sexual stages that link the two.

Option (1) WBC of human host — Incorrect. Plasmodium does not grow in white blood cells. After the liver, it attacks the red blood cells.

Option (2) RBC of human host — Correct. Inside the red blood cells the parasite multiplies, bursts them and causes fever. Some parasites then form male and female gametocytes, which develop in the red blood cells.

Option (3) Gut of mosquito — Incorrect. The gametocytes reach the mosquito when it sucks blood. In its gut fertilisation takes place; the gametocytes are not formed there.

Option (4) Saliva of anopheles mosquito — Incorrect. The salivary glands store the sporozoites, the infective stage injected into a new human at the bite.

NCERT Extract:
Common Diseases in Humans – “… Let us take a glance at the life cycle of Plasmodium (Figure 7.1). 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.”