Malaria
Read the following passage carefully and answer the given questions.
Plasmodium, a tiny protozoan is responsible for malaria. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Plasmodium enters the human body as sporozoites through the bite of infected female Anopheles mosquito. The parasites initially multiply within the liver cells and then attack the RBCs resulting in their rupture. The rupture of RBCs is associated with release of a toxic substance, which is responsible for the chill and high fever recurring every three to four days. When a female Anopheles mosquito bites an infected person, these parasites enter the mosquito’s body and undergo further development. The parasites multiply within them to form sporozoites that are stored in their salivary glands. When these mosquitos bite a human, the sporozoites are introduced in the body, thereby initiating the life cycle of parasite. It is interesting to note that the malarial parasite requires two hosts to complete its life cycle.
In Plasmodium life cycle, the fertilization and development of gametocytes take place in:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Mosquito gut
The male and female gametocytes of Plasmodium are formed in the human red blood cells. They are taken up by a female Anopheles mosquito when it bites an infected person. In the gut of the mosquito they fuse (fertilisation), and the zygote develops further. The parasite then multiplies to form sporozoites, which move to the salivary glands.
(1) Human liver cells — Incorrect. The parasite first multiplies here, after the mosquito bite. This is the asexual stage, and no fertilisation takes place.
(2) Mosquito salivary glands — Incorrect. The sporozoites are only stored here, ready to be passed to the next person.
(3) Mosquito gut — Correct. Fertilisation and the further development of the gametocytes take place here.
(4) Human red blood cells — Incorrect. The gametocytes are formed here, but they cannot fuse here. They have to be taken up by the mosquito.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.