Organisms and their Environment

• Nitrogen Fixation : taking atmospheric nitrogen and fixing it into an organism
• A population (definition) : "a group of organisms of one species, living in the same area at the same time."
• abiotic/biotic factors can act as limiting factors :

  definition : components that limit population growth

  examples :

  • competition
  • predation
  • parasites, disease
  • weather
  • natural disasters
• Define Ecosystem:

  A community of indterdependent organisms and their environment
• Define 'food chain':

  Representation of feeding relationships and energy flow amongst organisms
• Food Web

  Network of interconnected food chains
• Define trophic level:

  An organism's position in a food chain, food web, or food pyramid
• Define 'Consumer':

  An organism that obtains its food by feeding on other organisms
• Define 'Producer':

  An organism that makes its own food via energy from the sunlight (photosynthesis)
• Define 'Carnivore':

  An animal that eats other plants
• Define 'Herbivore':

  An animal that eats plants
• Define 'Decomposer':

  An organism that obtains food by breaking down dead organisms
• Energy Flow :

  Principle source of energy input into biological systems : Sunlight. Light energy is captured by plants, changed into chemical energy.

  Chemical energy in plants is transferred throughout the food chain.
• Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer