| Themes > Science > Zoological Sciences > Animal Phyla and Included Classes > Sub-Kingdom: Protozoa > Phylum Sporozoa |
All sporozoa are parasitic. There are several species of Plasmodium, all causing malaria in birds or mammals. They have complicated life cycles involving two hosts; with sexual stages in a mosquito and asexual stages in mammalian or avian blood. On demostration are slides of the adult stages of the malaria parasite in the stomach of a mosquito, and stages in human blood. The trophozoites from the salivary glands of a mosquito enter the human red blood corpuscles and are first observed as a ring stage, later dividing several times to form amultinucleated mass of merozoites. The release of merozoites may start new ring stage development in more erythrocytes to produce many more merozoites. Finally, however, some will develop into gamets instead of merozoites. These are large and have a single mucleus. No further development takes place in the human. Draw a trophozoite (ring stage) and several later schizogony stages. |
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