Food Chains/Webs, Energy Pyramids, and Ecological Relationships

Producer/Autotroph

An organism that makes its own food (plants)

Consumer/herterotroph

An organism that eats other organisms (animals)

primary consumers (herbivores)

consume producers

secondary consumers (carnivores)

obtain their energy by eating primary consumers

tertiary consumers (carnivores)

organisms in the fourth trophic level (eg, hawks and sea otters), which obtain their energy by eating secondary consumers

Carnivore

A consumer that eats only animals.

Herbivore

A consumer that eats only plants.

Omnivore

A consumer that eats both plants and animals

food chain

A series of events in which one organism eats another and obtains energy.

food web

a system of interlocking and interdependent food chains.

food chain vs food web

Chain is simplified illustrating energy flow and a web is a complex arrangement of food chains.

energy pyramid

Shows the amount of energy that moves from one feeding level to another in a food web

The amount of energy that transfer from one trophic level to the next in an energy pyramid.

10%

predator

An animal that hunts other animals for food

prey

an animal hunted or caught for food

Predation

An interaction in which one organism captures and feeds on another organism

competition

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

Mutalism

A symbiotic relationship in which both species of organisms involved in the relationship benefit.

Commensalism

A symbiotic relationship between two organisms of different species where one benefits and the other is neither harmed nor benefited

Parasitism

A symbiotic relationship in which one organism (the parasite) benefits and the other organism (the host) is harmed.

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

constant

something that stays the same

control group

the group that does not receive the experimental treatment.