1. Biotic Interactions

2. Symbiosis Symbiosis: Close interaction between two organsisms – usually a long term interaction

3. Predation Predation occurs when one organism consumes another organism for food. The organism that is consumed is the called the prey.

4. Competition Competition occurs when two or more organism compete for the same resource. Competing for resource takes energy. This energy takes away from the energy required for other important life processes such as growth and reproduction. Competition influences population size and the success of a group of organisms.

5. Mutualism Mutualism is when there is a relationship between organisms in which both organisms benefit.

6. Parasitism Parasites can be either plants or animals that feed on their “prey” over an extended period of time, typically without killing it immediately but usually causing it harm.

7. Commensalism Commensalism is a relationship in which one organism benefits and the other neither benefits nor suffers harm.