Question

Some of the events occur during the life cycle of Plasmodium are given below. Identify the correct statement.

• A. The sporozoites reproduce sexually in liver cells.
• B. The gametocytes develop in RBC.
• C. Femle mosquito take up sporozoites with blood meral.
• D. When mosquito bites a man, gametocytes are injected.

Answer 1

The correct option is B The gametocytes develop in RBC.

Plasmodium infection in humans begins when an infected Anopheles sp. mosquito takes a blood meal and injects infective sporozoites into the peripheral circulation. Within minutes, these sporozoites invade hepatocytes in the liver and, over approximately one week, undergo asexual multiplication, producing tens of thousands of merozoite forms of the parasite and released into the peripheral circulation. The merozoites invade red blood cells (RBCs) and complete another round of multiplication within 48–72 h, with the production of 16–20 additional merozoites per RBC, which devour the RBC hemoglobin in the process. Merozoites differentiate into male (microgametocyte) and female (macrogametocyte) sexual forms. These sexual forms are taken from the bloodstream by a feeding Anopheles sp. mosquito and fertilize in the mosquito midgut to form zygotes. These zygotes further differentiate into motile forms, called ookinetes, migrate through the mosquito gut wall and divide within oocysts on the external gut wall to form thousands of sporozoites.

Thus, the correct answer is option B.