Give differences: Commensalism and Mutualism.

Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called

Competition for food, light and space is most severe between two

Given below are two statements:

Statement $I$: Gause's competitive exclusion principle states that two closely related species competing for different resources cannot exist indefinitely.

Statement $II$: According to Gause's principle, during competition, the inferior will be eliminated. This may be true if resources are limiting.

In the light of the above statements, choose the correct answer from the options given below :

Describe commensalism.