biology topic 7

• what do organisms compete for?

  (F) Food, (w) Water ,(s) space, (l) light ,(C) CO2/O2
• what is the meaning of interdependence?

  organisms depending on each other for survival. when this happens a COMMUNITY is formed.
• what are abiotic factors?

  non-living factors
• what are biotic factors?

  the impact of other organisms on an ecosystem
• what are the examples of abiotic factors?

  light temperature moisture soil PHCO2 & O2 concentration
• what are the examples of biotic factors?

  food predators/prey / pathogens
• what is the sampling practical?

  place QUADRAT in random positions in area (10% of area) count number of chosen organisms in each. calculate mean then multiply by total area to estimate for population. moving it along a transect allows you to observe changes in population
• what is food chains?

  shows the direction of BIOMASS transfer between organisms
• what is

  producer (plants/algae) -> primary consumer (herbivore/omnivore) -> secondary consumer (carnivore/omnivore) -> Tertiary consumer (carnivore/omnivore)
• where on the food chain are apex predators?

  always at the top of the food chain
• what are apex predators?


  don't have natural predators
• life is ??????-based.

  Carbon-based
• what happens to carbon in life?

  Carbon is decomposes recycled when an organism dies and decomposes, as they excrete 2 while alive.
• what is the water cycle?

  rain (precipitation) -> runs into rivers, sea -> evaporation
• what is the meaning of biodiversity

  the variety of species of organisms that exist in an ecosystem
• what is an advantage of a high biodiversity?

  makes a stable ecosystem as organisms will be able to depend on a grater number of other species for survival
• what does human development cost?

  usually results in reduced biodiversity, due to the destruction of habitats
• why is land needed?

  for building, farming & disposing of waste
• why is PEAT BOGS being destroyed and what does that cost us?

  destroyed to make compost. reduces the biodiversity of that ecosystem, especially for organisms
• what does burning peat release?

  carbon dioxide (CO2)
• how much of a percentage is CO2 in the atmosphere?

  0.04%
• how much of a percentage is methane in the atmosphere?

  0.00018%
• what is water vapour responsible for?

  95% of the greenhouse effect
• what also reduces biodiversity?

  Deforestation
• what is a pyramid of biomass

  indicates how much biomass is transferred between trophic levels
• what happens to the biomass at each level

  it is lost at each level due not to all of it being consumed/absorbed
• what are the two concerns in the world?

  food security - changing diets & growing environments sustainable fishing - ensures that fish are not caught faster than they can breed