Ecosystems

• Biodiversity is the variety of all living organisms on planet Earth.
• Genetic diversity refers to the variety of genes or the number of different inherited characteristics present in a species. They are created through mutations or changes in an organism's DNA that is passed down to future generations.
• Adaptations


  A structural, behavioural or physiological feature that enhances the survival of an organism in particular environmental conditions
• Structural


  Physical features of an organism that enable them to survive in a given environment.
• Physiological


  Internal and/or cellular features of an organism that enables em to survive in a given environment
• Behavioural


  Activities that an organism performs in response to internal and external stimuli
• An ecosystem is the most complex level of organisation.
• Levels of Organisation

  A) Ecosystem

  B) Community

  C) Population

  D) Multicellular Organism

  E) Cell

  
• Population


  All the individuals of one particular species living in the same area at the same time.
• Community


  Made up of all the populations of various organisms living in the same location at the same time.
• Producers


  Members of an ecosystem community that bring energy from an external source into the ecosystem. E.g. plants

  No ecosystem can survive without producers
• Consumers


  Heterotrophs that must obtain their energy by eating other organisms or parts of them. All animals are consumers. E.g. herbivores, carnivores, omnivores and detritivores (eat decaying matter).
• Decomposers


  Heterotrophs that obtain their energy and nutrients from organic matter and wastes from consumers like faeces and shed skin. E.g. fungi, bacteria.
• Keystone Species


  Species whose prescence in an ecosystem is essential for the maintenance of that ecosystem. E.g. Elephants that maintain populations of trees in grassland environment
• Intraspecific Interactions


  Competition for resources between members of the same species
• Interspecific Interactions


  Competition for resources between members of different species
• Amensalism Interactions


  One organism is inhibited or destroyed, the other is unaffected.
• Predator-prey Interactions

  One species kills and eats the other
• Herbivore-Plant Interactions


  An animal eats a plant
• Parasitism

  An organism living on or within another organism to derive a benefit, whilst harming the host.
• Mutualism


  A beneficial relationship between two species
• Commensalism


  One member gains a benefit from the relationship, the other is unaffected.
• Competition


  Interaction between individuals of the same or different species that use one or more of the same resources in the same ecosystem
• Distribution


  Spread of members of a population over space.
• Uniform Distribution

  
• Random Distribution

  
• Clumped Distribution