Question

Motile zygote of Plasmodium occurs in
A) Salivary glands of Anopheles
B) Human RBCs
C) Human Liver
D)Gut of Female Anopheles

Answer 1

Plasmodium, a genus representing the unicellular eukaryotes are obligatory parasites thriving on vertebrates and insects for their food.

Complete answer:
Plasmodium is a tiny protozoan parasite which is responsible for the cause of malaria in humans. This organism is easily spread through the bite of the female Anopheles mosquito when it sucks the blood of infected humans. This results in the sucking up of gametophytes along with the blood meal which then reaches the lumen cavity of the mosquito.
Option A: Salivary glands of the female Anopheles secrete several proteins. Thus, this is an incorrect option for the given question.
Option B: Plasmodium is a human parasite and hence, human RBCs cannot be the site of storage of its motile zygote. Thus, this is an incorrect option.
Option C: Human liver is responsible for the secretion of bile. Thus, this is an incorrect option.
Option D: After the female Anopheles bites an infected person, it harbours the malarial parasite, Plasmodium into the gut of its lumen. Thus, this is the correct option.
Zygote stage of the Plasmodium is defined as a diploid stage formed out of a physical fusion between male and female gamete. This phase is characterised by meiosis which later gives rise to ookinetes.
The motile zygotes of these Plasmodium are present within the gut of the females of the malaria causing vector called as Anopheles mosquitoes. Along with the RBCs’, both the microgametophyte and megagametophyte enter into the gut where they unite to result in the production of a diploid motile zygote. This zygote further results in the formation of an ookinete which subsequently undergoes sporulation to result into the formation of sporozoites which then enter males to complete their cycle of asexual reproduction.
Therefore, the correct option is (D) Gut of Female Anopheles.

Note: Over the course of time, a number of pharmaceutical drugs have been developed against the Plasmodium infection. However, the malarial parasite was successful in acquiring resistance to each of the newly developed drugs.