Parasitism
It is the relationship in which an organism (parasite) obtains nutrients from another live organism (host) without killing it.
A parasite obtains food and shelter from the host while causing the host harmful effect.
Ectoparasites are parasites found on the surface of a host e.g. ticks
Endoparasites are parasites found inside the body of the host e.g. tapeworms
Parasites weaken their hosts, cause or transmit diseases, which may kill their hosts thus reducing their numbers and distribution.
Question
State the differences and similarities between predation and parasitism. (4 marks)
Symbiosis
It is an association between organisms of different species in which both organisms benefit.
Example; Rhizobium bacterium which live in the root nodules of leguminous plants.
The plants benefit from the nitrates fixed by Rhizobium bacteria while the bacteria benefits from shelter and carbohydrates provided by the plants. This relationship enables such plants to thrive on nitrogen deficient soils.
