Question

The secondary host for the parasite Plasmodium was discovered by
a) Rossen Von Rosenhof
b) Charles Laveron
c) Darwin
d) Ronald Ross

Answer 1

Hint: The scientist was born in 1857, 13 May and was a General in the English army. Plasmodium is an infectious agent that causes malaria. Two hosts are required by the plasmodium to complete its life cycle. Plasmodium is an obligate parasite.

Complete answer:
Mosquitoes transmitting the malaria parasite was observed by the scientist Ronald ross who was working in India when he noticed them. He reported that the development of the plasmodium sp. took place in mosquitoes.

Additional information:
- Darwin gave the theory of evolution and India named it as the theory of Darwin.
- Plasmodium causes malaria. There are other species involved which cause different types of diseases – Plasmodium vivax, plasmodium ovale, plasmodium falciparum. The malarial parasite life cycle involves two hosts. When a mosquito bite human it then injects sporozoites into the host body. These sporozoites then travel to the liver and cause an infection there. They then mature and produce merozoites. This is the infective stage. Merozoites then infect the blood cells to form trophozoites. When a mosquito bites this person, it takes in the parasites along with the blood. The parasites then multiply in the mosquito. In mosquitoes' stomachs, microgametes change into zygotes. The zygotes then change into oocysts that grow, rupture and release sporozoites. These sporozoites travel to the saliva of the mosquito and the mosquito then bites new human host transmitting the infection. Diagnosis of malaria can be done by a rapid test in which blood smear is examined of the infected person. Malaria can be treated by chloroquine.
So, the answer is ‘Ronald Ross’.

Note: Ronald Ross discovered malarial parasites and Hans Andersag discovered the anti- malarial drug. He was awarded the Nobel Prize in 1902 for Physiology and Medicine. He became the first British doctor to receive a Nobel Prize.