Concept:The life cycle of
Plasmodium involves two hosts: humans (asexual phase) and female
Anopheles mosquitoes (sexual phase).
Key Fact:The correct sequence begins with the injection of infectious sporozoites, followed by liver schizogony, blood schizogony, and finally formation of gametocytes.
Explanation:First, a female
Anopheles mosquito injects sporozoites into the human bloodstream during a bite (Stage E).
These sporozoites travel via the bloodstream and reach the liver (Stage D).
Inside liver cells, the parasites undergo multiple rounds of asexual reproduction (schizogony), which eventually bursts the liver cells and releases thousands of merozoites into the blood (Stage B).
The merozoites then invade red blood cells (RBCs) and continue asexual reproduction, leading to the rupture of RBCs and causing the classic fever cycles (Stage A).
After several cycles, some merozoites differentiate into male and female gametocytes that develop inside the RBCs (Stage C).
These gametocytes are taken up by another mosquito during a blood meal, completing the cycle.
Answer:The correct sequence is
E,D,B,A,C, which corresponds to option A.
