What is Plasmodium?
{{italictitle}} {{Taxobox | image = Malaria.jpg | image_caption = ''Plasmodium'' sporozoite | regnum = [[Chromalveolata]] | superphylum = [[Alveolata]] | phylum = [[Apicomplexa]] | classis = [[Aconoidasida]] | ordo = [[Haemosporida]] | familia = [[Plasmodiidae]] | genus = '''''Plasmodium'''''}} '''''Plasmodium''''', commonly known as the '''malaria parasite''', is a large [[genus]] of [[parasitic]] [[protozoa]]. There are about 200 [[species]].<ref>Garnham P.C.C. 1966. ''Malaria parasites and other haemosporidia''. Oxford: Blackwell. {{ISBN|0397601328}}</ref> Infection with these protozoans is called [[malaria]], a deadly [[disease]] widespread in the [[tropics]]. The parasite always has two hosts in its [[Biological life cycle|life cycle]]: a [[mosquito]] [[vector (biology)|vector]] and a [[vertebrate]] host. The life-cycle is very complex. There is a sequence of different stages in the vector and the host.<ref>Shortt H.E. 1951. Life-cycle of the mammalian malaria parasite. ''Br. Med. Bull''. '''8''' (1): 7–9. [http://bmb.oxfordjournals.org/content/8/1/7.long]</ref> These stages include: #[[sporozoite]]s which are injected by the mosquito vector into the host's blood; #hypnozoites which may rest undetected in the liver for up to 30 years; #merosomes and merozoites which infect the [[red blood cell]]s ([[erythrocyte]]s) of the blood; #[[trophozoite]]s which grow in the red cells, and [[schizont]]s which divide there, producing more merozoites which leave to infect more red cells; #gametocytes, male and female sexual forms, which are taken up by other mosquitoes. In the mosquito's midgut, the gametocytes develop into #[[gamete]]s which [[fertilization|fertilize]] each other to form motile #[[zygote]]s which escape the gut, only to grow into #new sporozoites which move to the mosquito's [[salivary gland]]s, from where they are injected into the mosquito's next host, infecting it and restarting the cycle. The genus ''Plasmodium'' was first described in 1885. At least ten species infect humans. Other spe