Ecosystems and material cycles

• trophic level

  the feeding level of an organism
• producer

  an organism that starts the food chain at the first trophic level, must make its own food, e.g by photosynthesis
• primary consumer

  organisms at a feeding level that eats the producers
• secondary consumer

  organisms at a feeding level that eat the primary consumers
• tertiary consumers

  organisms at a feeding level that eat the secondary consumers
• food chain

  shows a single link between organisms that eat eachother
• food web

  shows multiple links between feeding organisms that eat eachother
• population

  a group of one species living in the same area
• community

  all the organisms that live and interact in an ecosystem
• ecosystem

  an area which all the living organisms (biotic) and non living (abiotic) factors form a stable relationship
• biotic

  living factors in an ecosystem that affect other living organisms e.g disease, parasite, food availability
• abiotic

  non living factors that can influence where an organism lives e.g sunlight, water availability, temperature
• interdependent

  how species depend on each other for resources in a community
• habitat


  where an organism lives
• parasitism

  relationship between 2 species of plants or animals in which one benefits at the expense of the other, sometimes without killing the host
• mutualism

  association between 2 organisms of 2 different species in which each benefits
• pyramid of biomass

  pyramid constructed using the dry mass of an organism, always pyramid in shape
• pyramid of numbers

  pyramid constructed using the number of organisms in a food chain
• random sampling

  method used to estimate population of plants in an even area
• transect sampling

  method used sample plants in an uneven area
• quadrat

  a square frame used to sample plants in