Question

Signet ring stage of Plasmodium represents
A) Beginning of schizogony in liver cells
B) End of schizogony in RBC
C) Beginning of schizogony in RBC
D) Beginning of sporogony in humans

Answer 1

Hint:Early stage of malaria production in the red blood cell; the parasite cytoplasm is staining along its circular margin and the nucleus is stained red in Romanowsky stains, while the central vacuole is clearly visible as a ring.

Complete answer:
Plasmodium is a genus of single-cell eukaryotes, which is a compulsory vertebrate and insect parasite. The plasmodium's life cycle includes a host which is a blood-feeding insect and then injected with parasites during a blood meal into a vertebrate host. Until entering a bloodstream, parasites develop in vertebrate body tissue (usually liver) to infect red blood cells. Host red blood cells can then be killed and malaria may lead to diseases. During this infection, a blood-feeding insect (mostly mosquitoes), which continues the life cycle, catches a few parasites.

The period between the RBC and the trophozoite is a signet ring stage. The larva of merozoite becomes a trophozoite that develops by feeding RBC haemoglobin. At the centre of the cytoplasm, a new vacuole emerges, moving the nucleus to one side to create an illusion of a circle. It looks like the signet ring with the nucleus peripherally placed looks like a ring gem. Erythrocytic Schizogony ends when merozoite is produced by breaking RBCs. Each sporozoite is grown into a spherical, unpigmented schizont in liver schizogony. Sporogony occurs in the female anopheles mosquito.

Thus, the correct answer is option C. i.e., Beginning of schizogony in RBC.

Note:The plasmodium's life cycle includes a host which is a blood-feeding insect and then injected with parasites during a blood meal into a vertebrate host. Until entering a bloodstream, parasites develop in vertebrate body tissue (usually liver) to infect red blood cells.