Interactions of Living Things

Ecology Part II

What is an ecological niche?

•The place where an organism lives and that provides the things the organism needs is called its habitat.

What is an ecological niche?

•An organism's particular role, or how it makes its living, is called its niche.

http://chandra.as.utexas.edu/~kormendy/4FEC0444a.jpg

Interactions Among Living

Things22.3

Three major types of interactions•competition •predation •symbiosis.

How does

competition

relate to

ecosystems?

Competition is the struggle between organisms to survive in a habitat with limited resources.

Explain how predator-prey relationships affect populations in an ecosystem.

Predation is an interaction in which one organism kills and eats another organism. Predator Prey

Predators have adaptations that help them catch and kill their prey.

Prey organisms have adaptations that help them avoid being caught and eaten.

Predation can have a major effect on the size of a population.

Symbiosis is a close relationship between two species that benefits at least one of the species.

Mutualism : both species benefit.

Commensalism : one species benefits ; the other is neither helped nor harmed.

Demodex mites

Parasitism: Parasite (lives on or in) benefits; host is harmed.

Tapeworm head