Read the passage and answer the following question:
Some of the human diseases are caused by protozoans too. You might have heard about malaria, a disease man has been fighting since many years. Plasmodium, a tiny protozoan is responsible for this disease. 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 (infectious form) through the bite of infected female Anopheles mosquito. The parasites initially multiply within the liver cells and then attack the red blood cells (RBCs) resulting in their rupture. 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 mosquitoes bite a human, the sporozoites are introduced into his/her body, thereby initiating the events mentioned above. The malarial parasite requires two hosts – human and mosquitoes – to complete its life cycle; the female Anopheles mosquito is the vector (transmitting agent) too.
Read the following statements:
A. Plasmodium requires two hosts, human and mosquito, to complete its life cycle.
B. The female Anopheles mosquito is the vector (transmitting agent) of the malarial parasite.
C. The sporozoites formed inside the mosquito are stored in its gut.
How many of the above statements are correct?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Only two
The life cycle of Plasmodium runs partly in humans and partly in the mosquito. The sporozoites have to reach a new human through a bite, so they must be kept in a part of the mosquito that the bite uses.
Statement A: Plasmodium requires two hosts, human and mosquito, to complete its life cycle. — True. The passage states that the malarial parasite requires two hosts – human and mosquitoes – to complete its life cycle.
Statement B: The female Anopheles mosquito is the vector (transmitting agent) of the malarial parasite. — True. The passage states that the female Anopheles mosquito is the vector (transmitting agent) too.
Statement C: The sporozoites formed inside the mosquito are stored in its gut. — False. The passage states that the sporozoites are stored in the salivary glands. From there they are introduced into a human when the mosquito bites.
So statements A and B are correct, which makes two correct statements.