Plasmodium reproduces both in its mosquito hosts and in animal cells; the reproduction in mosquitoes is sexual, with two cells fusing to form cells with a recombined genetic code, but it uses asexual binary fission in animal cells. It has multiple life stages.
Plasmodium is the genus of the organism that causes malaria. The genus has about 200 species in it, of which at least 10 infect humans. The organisms first move to the liver, where they can remain dormant for as long as 30 years. Large groups of cells then move to the blood vessels of the lungs where they embed and are slowly released into the blood. They then invade red blood cells, where they reproduce. The daughter cells then escape to infect yet more blood cells. Some of these cells change into male and female forms for the next stage in the process.
The male and female forms are taken in by mosquitoes along with blood, after which they move to the mosquito's midgut and reproduce. They then transform into another form and split into several tiny cells, which move to the mosquitoes' salivary glands. From there, they are injected into an animal host where the cycle begins again.