ORGANISMS

__________________________________________________________________________________________________________

Organisms are the individual living members of an ecosystem.

Organisms of the same type; such as deer, trout, owls, ferns, moss, mice, bears, or oak trees, are called a population.

All the various populations combined than become the living componant of an ecosystem called a community.

_______________________________________________________________________

Sometimes organisms live in such close relationships that at least one of the organisms is helped by the other. Such a relationship is called a symbiotic relationship.

Symbiosis means living together.

Parasitism is one kind of symbiotic relationship. A parasitic relationship is one in which one organism is helped and another one harmed. Fleas, for example, are parasites on dogs and cats.

Mutualism is a relationship that helps both organisms. For example, a honeybee gathers pollen and nectar froma plant's flower. This gives food to the bee. The bee also pollinates the flower, helping the plant reproduce.

Lichen is another example of mutualism. Lichen is actually two kinds of organisms, fungi and algea, living together. The algea carry out photosynthesis to make food to feed which also feeds the fungi. In turn, the fungi supply water and minerals for the algea.

______________________________________________________________________________________