Chapter 4: Ecology

ecology

the study of living organisms, their interactions with each other and their abiotic environment

habitat

the place where an organism lives and to which it has adapted

population

a group of individuals of the same species living and breeding in the same habitat

community

A population of different species living and interacting with each other in the same habitat

ecosystem

a community of organisms and their abiotic environment

biosphere

The part of the Earth inhabited by living organisms

Producer

An organism that makes its own food

Consumer

An organism that takes food from another organism

Decomposer

An organism that breaks down dead organic matter

Saprophyte

Bacteria and fungi that feed on dead organic matter

Food chain

A sequence of organisms in which one is eaten by the next member of the chain

Primary consumer

An animal that feeds on producers

Secondary consumer

An animal that feeds on primary consumers

Tertiary consumer

An animal that feeds on secondary consumers

Trophic level

The feeding stage in a food chain

Food web

Two or more interlinked food chains

Nutrient recycling

The way in which elements are exchanged between the living and non living components of an ecosystem

competition

the struggle between organisms for a resource that is in short supply

predation

the catching, killing and eating of an organism

symbiosis

a close relationship between two organisms of different species in which at least one of them benefits

pollution

any undesirable change in the environment

pollutants

substances that cause undesirable changes in the environment

niche

the functional role of a species in an ecosystem

predator

an animal which kills other animals to use as a source of food

ectoparasites

parasites that live on the body of a host

endoparasites

parasites that live inside the host

contest competition

an active physical confrontation between two organisms which allows one to win the resource

scramble competition

when each organism tries to acquire as much of the resource as possible

mutualism

a symbiotic relationship where both species benefit from the interaction

flora

the plants in an ecosystem

fauna

the plants in an ecosystem

quantitative study

a study to find out the number of organisms that exist in an ecosystem

qualitative study

a study to find out the presence or absence of organisms in an ecosystem

adaptations

ways in which a species is specialised to survive in its competition