Question

A person suffering from a disease caused by Plasmodium, experiences recurring chill and fever at the time when
A. The microgametocytes and mega gametocytes are being destroyed by WBCs.
B. The sporozoites from RBCs are being rapidly killed and broken down inside spleen
C. The trophozoites reach maximum growth and give out certain toxins
D. The parasite after its rapid multiplication inside RBCs ruptures them, releasing the stage to enter fresh RBCs.

Answer 1

Hint: Plasmodium is a malaria-causing genus of parasitic protozoans. When the infected female Anopheles mosquito bites human beings or some other animal, malaria occurs. P. malariae, P. vivax, P. ovale are among several plasmodium species known to transmit Malaria. As it uses an insect (mosquito) as a medium to transmit and spread the disease.

Complete answer:
Plasmodium parasites have a complex life cycle which includes the following three stages:
Stage 1: During a blood meal, the microgametocytes and microgametocytes are passed on by an anopheles mosquito. The gametocytes grow into a sporozoite within the mosquito. Within the gut of the mosquito, the male and female gametocytes mate and develop a parasite termed sporozoite after 15 to 18 days.
Stage 2: When the infected anopheles feeds on human blood, the sporozoites are transferred via the saliva into the bloodstream circulation. The sporozoites reach the liver cells after that, and they grow into schizonts here. Later, merozoites are ruptured and released by these sporozoites.
Stage 3: Merozoites leave the lever and enter the bloodstream yet again, attacking the red blood cells there. Although killing all the blood cells in that process, the merozoites expand and multiply further. Some merozoites grow into gametocytes, which a mosquito later ingests into the bloodstream and the entire cycle begins again. When the merozoites kill red blood cells, a toxin is released that triggers bone-shaking chills and fever.

So, the correct answer is option (D).

Note: Today, malaria is one of the world's main causes of preventable death. There are two approaches to cope with malaria: preventing the incidence of mosquito bites (i.e. preventive steps) or fighting the parasites after the body has been infected. The treatment uses a chemical that is found in the bark of a cinchona tree called Quinine. While it is not a vaccine, a form of the drug chloroquine has been known to be very efficient against malaria.