Question

Man in the life cycle of Plasmodium is
A. Primary host
B. Secondary host
C. Intermediate host
D. None of these

Answer 1

Primary host is a host which first takes the parasites and secondary host is a host where the mosquito releases the sporozoites and the parasite lives only for a short period.

Complete answer:
In the life cycle of Plasmodium, Primary host is a host that first takes in the parasite by feed on the blood of an infected person and this infected person will be the intermediate host from where this mosquito carry the parasite and then this mosquito will bite the human beings and infect them, humans will be the secondary host.
So, Primary host in the life cycle of Plasmodium is the female Anopheles mosquito which feeds on the blood of an infected person and takes in the parasite.
Secondary host in the life cycle of Plasmodium is man because when this mosquito carrying the parasite bites the human then the sporozoites are released and that parasite enters into the human body and infect them as well. So, man and other vertebrates are the secondary host.
If we look at options now, option A is Primary host. It is an incorrect option since, primary host is the female Anopheles mosquito which feeds on the blood of an infected person. Therefore, this option is eliminated since man is not the primary host.
Moving to option B which is Secondary host. It is the correct option since the secondary host is a host which lets the parasite live only for a short transition period and this mosquito will bite humans and release sporozoites. Therefore, this option is the correct one.
Moving to option C which is Intermediate host, it is also the incorrect answer since man is secondary host not intermediate host. Therefore, it gets eliminated.
Last option D is None of these. It is an incorrect option as Man is the secondary host in the life cycle of Plasmodium and secondary host is given in the option B.

Thus, the correct answer is option B which is Secondary host.

Note: Mosquito first takes the parasite by feeding on the blood of an infected person and hence this mosquito is a primary host and then this mosquito bites the man and releases the parasite there but in man this parasite lives for a short period and hence man is a secondary host.