species, communities and ecosystems

species

Organisms that belong to the same species can mate AND produce FERTILE offspring.

populations

consists of all the organisms of a given species that live in a particular area.

communities

form by populations of different species living together and interacting with each other.

ecosystem

A community forms an ecosystem by its interactions with the abiotic factors that are found in its environment.

biotic factors

* plants
* animals
* bacteria

abiotic factors

* climate
* rainfall
* temperature
* soil nutrients
* wind
* light

autotroph

Organisms which can synthesise organic material from inorganic sources provided by their environments.

heterotroph

Organisms which derive their energy from consuming other organisms

producers

Organisms that produces their own energy through processes such as photosynthesis in plants or chemosynthesis in bacteria.

consumers

Consumers feed on living organisms by ingestion.

decomposers

Organisms that break down organic matter and play an important role in food webs and nutrient cycling

* detritivores -obtain their organic nutrients from detritus (decomposing plant and animal matter) by internal digestion
* saprotrophs - obtain their organic nutrients from dead organisms by external digestion.

nutrient cycling

use, movement, and recycling of nutrients in the environment. Producers, consumers and decomposers allow nutrients to be cycled through an ecosystem.