The organism in the environment

• Producers: plants which photosynthesise to produce food
• Consumers: animals that eat plants or other animals
• Decomposers: organisms that break down dead material to help recycle nutrients
• Population: all the organisms of a particular species found in an ecosystem
• Community: two or more populations of organisms
• Habitat: the place where an organism lives (an ecosystem contains a variety of habitats)
• Ecosystem: a community of animals, plants, microorganisms, non living things and their shared environment.
• Abiotic factors that affect the population size and distribution of organisms: physical or chemical factors including:

  • climate, light intensity, temperature, water availability
  • hours of daylight
  • soil conditions and water content, pH
  • salinity (salt content) in an estuary
  • pollution
• Biotic factors that affect the population size and distribution of organisms: biological factors including:

  • availability of food
  • predation
  • paratism
  • disease
  • pollinating insects
  • nest sites