People call someone who lives off another person a ‘parasite’. Perhaps a guest who refuses to leave. In biology, a parasite is an organism which can exist and/or reproduce at the expense of the organism with which it lives, the host.
People call someone who lives off another person a ‘parasite’. Perhaps a guest who refuses to leave. In biology, a parasite is an organism which can exist and/or reproduce at the expense of the organism with which it lives, the host.
All sizes and shapes
Parasites come in all sorts of shapes, from animals to plants, and from fungi to viruses. The unicellular organism, plasmodium, which causes malaria is a well-known parasite. It is spread to humans by the malaria mosquito.
Fatal guest
The parasite needs a host to survive and/or to reproduce. In doing so, it harms its host. This is why parasites are often looked upon as pathogens (causing disease). Some parasites can even kill their hosts.