Question

The infective stage of Plasmodium is

• A. Trophozoite
• B. Cryptozoite
• C. Sporozoite
• D. Merozoite

Hint:

Think about which parasite form the mosquito actually injects into the bloodstream.

Answer 1

The Correct Option is C

This question tests knowledge of which Plasmodium stage starts human infection.

1. Trophozoite: the growing stage inside red blood cells, appears after infection is already established.
2. Cryptozoite: the liver-stage form that develops from sporozoites, a step after the infective bite, not the infective form itself.
3. Sporozoite: delivered directly from the mosquito's salivary glands into the bloodstream during a bite, making it the stage that actually causes human infection.
4. Merozoite: invades red blood cells during the blood-stage cycle but is not the form transmitted by the mosquito bite.

Correct answer: Sporozoite