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Human Health and Disease — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease4 Marks
Question
Explain the life cycle of Plasmodium (with diagram).
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Answer

→Plasmodium enters the human body in the form of sporozoites when an infected female Anopheles mosquito bites a human.
→Initially this parasite multiplies in the liver cells and then invades the blood cells causing RBC's to rupture.
→Rupture of RBC releases a toxic substance called hemozoin, which causes chills and high fever for 3 to 4 days.
→At this stage, when a female Anopheles mosquito bites an infected person, the parasite enters the mosquito's body, where it develops further.
→There they multiply and form sporozoites.
→This sporozoite is stored in the salivary gland of the mosquito.
→When this infected female mosquito bites a person, the parasite enters her body and develops.
→Malaria parasite requires two hosts to complete its life cycle,
(1) Man,(2) Mosquitoes.
→Reproduction in Plasmodium
→Asexual reproduction in humans:
→The parasite reproduces in the human RBC and destroys the RBC.
→In RBC the sexual stage (germ cells) develop male and female germs (male- microgamete, female-mega gamete).
→These genes enter mosquitoes from humans through mosquito bites.
→Sexual reproduction in mosquito:
→The sexual genes (Gametes) entered into the mosquito from the human being are fertilized in the intestine of the mosquito and induce development.
→In order to develop, the sporozoite stage is stored in the salivary gland of the mosquito.
→Malaria is a disease caused by Plasmodium- like parasites in humans.
→Different species of Plasmodium like (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale) are responsible for different types of malaria.
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