Ecology: Chapter 1, Section 3 Interactions Among Living Things

A characteristic that makes an individual better suited to its environment may eventually become common in that species

The behaviors and physical characteristics that allow organisms to live successfully in their environments

• The role of an organism in its habitat, or how it makes its living
• The niche includes the type of food the organism eats, how it obtains its food, & which other organisms use the organism as food

• 1. Competition
• 2. Predation
• 3. Symbiosis

Struggle between organisms to survive as they attempt to use the same limited resources

An interaction in which one organism kills another for food

An organism that does the killing

The organism that is killed

Populations of predators and their prey rise and fall in related cycles

Running fast, tentacles of poison, stingers, big eyes, mimicry, protective covering, camouflage, and false coloring

A close relationship between two species that benefits at least one of the species

• 1. Mutualism
• 2. Commensalism
• 3. Parasitism

A relationship in which both species benefit

A relationship in which one specie benefits and the other is neither helped nor harmed

Involves one organism living on or inside another organism and harming but not killing it

• The organism that benefits in a parasitic relationship (usually smaller than the host)
• Example: Fleas, ticks, leeches, and tapeworms

The organism that a parasite lives on or in. The host is harmed by the parasite.