Where will you look for the sporozoites of malarial parasite?

To find the sporozoites of the malarial parasite, we need to understand the life cycle of the parasite and its transmission to humans. Malaria is caused by the Plasmodium parasite and is primarily transmitted through the bite of an infected female Anopheles mosquito. Let's examine the options given and explain why the correct answer is option 'A' - saliva of infected female Anopheles mosquito.

a) Saliva of infected female Anopheles mosquito
- When an infected female Anopheles mosquito bites a human, it injects saliva into the human's bloodstream to prevent blood clotting. Along with saliva, it also injects sporozoites, which are the infective form of the malarial parasite.
- These sporozoites travel through the bloodstream and eventually reach the liver, where they invade liver cells and undergo asexual replication.
- From the liver, they are released back into the bloodstream as merozoites, which invade and multiply within red blood cells, causing symptoms of malaria.

b) Salivary glands of freshly molted female Anopheles mosquito
- This option is incorrect because the sporozoites are not found in the salivary glands of freshly molted female Anopheles mosquitoes. It is only when the mosquito becomes infected by feeding on an infected human that the sporozoites develop and reach the salivary glands.

c) Spleen of infected humans
- The spleen plays a role in the immune response against malaria, but it is not the site where sporozoites are found. Sporozoites are injected into the bloodstream by infected mosquitoes and primarily invade liver cells, not the spleen.

d) Red blood corpuscles of humans suffering from malaria
- While red blood cells are indeed the target of the malarial parasite during the blood stage of infection, sporozoites are not found within red blood cells. Sporozoites are injected into the bloodstream by infected mosquitoes and initially invade liver cells, not red blood cells.

In conclusion, the correct answer is option 'A' - the sporozoites of the malarial parasite are found in the saliva of infected female Anopheles mosquitoes. When these infected mosquitoes bite humans, they inject sporozoites along with saliva into the bloodstream, initiating the infection process.