Question

Which of the following is the infective stage of Plasmodium in the secondary host?

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

Answer 1

Answer: (B)

Life cycle of Plasmodium requires two hosts to complete its life cycle: human (host) and female Anopheles mosquito (vector).
A. Female Anopheles mosquito bites the human and releases sporozoites in the blood.
B. Multiplication of parasites in the liver cells.
C. Entry of parasite into RBCs $\to$ Rupture of RBCs $\to$ Release of a toxic substance -Haemozoin $\to$ Haemozoin causes chills and high fever repeating in every 3 to 4 days.
D. Female Anopheles mosquito bites an infected person $\to$ Parasites enter the mosquito's body (gut) and undergo further development.
E. Multiplication of parasites within the body of mosquito to form sporozoites $\to$ Sporozoites are stored in the salivary glands.
F. Step A-E is repeated.