Adaptations, interdependence and competiton

• Ecosystem


  The interaction between a community of living organisms and their environment
• Community


  All the organisms that live in a habitat (plants and animals)
• Population


  All of the members of a single species that live within a geographical area
• Species


  A type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully
• Levels of organisation within an ecosystem


  • Producer
  • Primary consumer
  • Secondary consumer
  • Tertiary consumer
• Producer


  Plants and algae, which photosynthesise
• Primary consumer


  Herbivores, which eat producers
• Secondary consumer


  Carnivores, which eat primary consumers
• Tertiary consumer


  Carnivores, which eat secondary consumers
• Interdependence


  The fact that all organisms that live in an ecosystem depend upon each other, for food, protection, shelter, etc, in order to survive
• Food chain


  A sequence (usually shown as a diagram) of feeding relationships between organisms, showing which organisms eat what and the movement of energy through trophic levels
• If the foxes in the food chain above were killed, the population of rabbits would increase because they are no longer prey to the foxes. As a result the amount of grass would decrease because the increased population of rabbits would be eating it
• Often very small changes to ecosystems have large consequences, which can be difficult to predict
• Photosynthesis


  A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic
• Competition


  Photosynthesising plants and algae in an ecosystem compete for light, space, water and minerals from the soil. Animals in an ecosystem compete for food, mates and their territory
• Intraspecific competition


  The competition between organisms within the same species
• Organisms which have more of these resources tend to grow more healthily and are more likely to have offspring
• Stable community


  A community in which the size of the populations of all species remain relatively constant over time