14.2 Community Interactions

OBJECTIVES

Students will learn that competition and predation are two important ways that organisms interact AND that symbiosis is a close relationship between species.

14.2 Community Interactions

KEY CONCEPT Organisms interact as individuals and as populations.

14.2 Community Interactions

Competition occurs when two organisms fight for the same limited resource.

Intraspecific competition:2 of the same species compete for a resource

Ex: 2 tigers fighting for a kill or a mate

14.2 Community Interactions

Interspecific competition: 2 different species fighting over the same resources

Ex: A lion and a hyena fighting over a kill

14.2 Community Interactions

• Predation occurs when one organism captures and eats another.

14.2 Community Interactions

• There are three major types of symbiotic relationships.

1) Mutualism: both organisms benefit

Egyptian Plover and crocodile Bat and Saguaro cactus

14.2 Community Interactions

2) Commensalism: one organism benefits, the other is unharmed

Ex: Cattle Egret- The cattle disturb insects as they graze, making it easy for Egrets to find their meals

14.2 Community Interactions

3) Parasitism: one organism benefits, the other is harmed

– ectoparasites (such as leeches) live on the outside of the body

– endoparasites (such as hookworms) live inside the body