a parasite is a living organism that uses the resources of another living organism (called the ‘host’), without providing any benefit to the host. The word ‘parasite’ means ‘to eat at another’s table’, so parasites are a bit like an uninvited dinner guest! They come in many shapes and sizes, from tape worms that can be over a metre long living in the gut, to single-celled parasites like Plasmodium (which cause malaria and live inside red blood cells) and Leishmania (which cause a disease called leishmaniasis and live inside immune cells called macrophages), and even biting insects that live outside the body, but feed on the blood of their hosts like mosquitoes, sandflies, blackflies, kissing bugs, leeches and ticks.
Comments
Mark commented on :
Claire has answered this perfectly apart from length of the tapeworm. They can grow to tens of metres!