Different species compete to survive and breed. The size of a predator population depends on the size of the prey population, and the reverse is true as well. Mutualism benefits both species involved in the relationship, but parasitism only benefits the parasite, not the host.

Competition

Habitats have limited amounts of the resources needed by living organisms. Organisms must compete with others in order to get enough of these resources to survive. If they are unsuccessful and cannot move to another habitat, they will die.

A niche is a particular place or role occupied by an organism within an ecological community. Similar species will occupy similar niches. For example, red squirrels and grey squirrels are two different species. They occupy similar but slightly different niches.

The two main types of competition are:

• interspecific competition, which happens between individuals…