Malaria. Coloured scanning electron micrograph (SEM) of a Plasmodium falciparum protozoan with red blood cells. These protozoa (yellow) cause malaria. The disease is spread by bites from infected tropical mosquitoes (Anopheles sp.). Here, the plasmodium is exflagellating. This is the process which forms a male microgamete (sex cell), and only occurs in the stomach of an infected mosquito, or in vitro, and never in humans. The disease destroys red blood cells, leading to anaemia, and mis-shapen infected blood cells can block blood vessels, leading to kidney failure, coma, and death. Magnification: x2650 at 6x6cm size.