Levels of organisation

• define population

  species that occupy the same habitat
• define habitat

  place in which an organism lives
• define community

  populations of different species interacting
• define ecosystem

  interactions between biotic and abiotic factors in an area
• what do food chains show?

  feeding relationships of different organisms and the flow of energy between the organisms
• define biomass

  total mass of living material
• what are trophic levels?

  stages in a food chain
• what do arrows in a food chain represent?

  direction of biomass transfer
• describe a simple food chain

  producer > primary consumer > secondary consumer > tertiary consumer
• what is a producer?

  organism that makes its own food
• what types of organisms are primary producers?

  photosynthetic organisms like green plants and algae that trap energy from the sun
• what is a primary consumer?

  organism that feeds on producers
• what is a secondary consumer?

  organism that feeds on primary consumers
• what is a tertiary consumer?

  organism that feeds on secondary consumers
• what is a predator?

  consumer that kills and eats other animals
• what is prey?

  animal that is killed and eaten by another animal
• describe the pattern of predators and prey in a stable community

  number of predators and prey rise and fall in cycles
• why are producers the first trophic level?

  • provide all biomass for the food chain (production of glucose via photosynthesis)
  • rest of the food chain involves the transfer of this biomass
• piece of apparatus used to measure the abundance and distribution of organisms in an area

  Quadrat
• piece of apparatus used to study the distribution of organisms across a gradient

  belt transect