• Created by: Holly45
  • Created on: 09-03-15 17:26


  • outlines your sample area
  • used to investigate the size of a population of plants or slow moving animals
  • must choose areas at random
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  • not random
  • sample the organisms along a line at regular intervals
  • shows how the distribution of organims changes along that line
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Organisms in their environment

  • temperature (limiting factor)
  • nutrients (level of mineral ions and plants struggle to grow in areas with low levels of mineral ions)
  • amount of light (some plants are adapted to living in low light levels and affects the distribution of animals and plants)
  • availability of water (distribution changes after it rains)
  • availability of oxygen or carbon dioxide (carbon dioxide is a limiting factor and plants are more vulnerable in areas of low carbon dioxide)
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The green house:

  • speeds up the growth of plants
  • produces higher yeilds
  • inside it's easier to control the environment

Controlling a crops environment:

  • continuous interactions between the different factors
  • in the morning, light levels and temperature may limit the rate of photosynthesis

Control though technology:

  • hydroponics (when plants grow in water)
  • turnover is fast
  • costs lots of money
  • levels are varied to get the fastest rates of photosynthesis
  • controls light, temperature and carbon dioxide
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How plants use glucose

  • can be used to make amino acids (combine sugars with nitrate ions)
  • provides energy
  • built up into more complex carbohydrates like cellulose
  • some glucose is changed into starch for storage
  • food for the plant is moved around the plant in the phloem
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Limiting factors

  • light (brighter light means faster rate of photosynthesis)
  • temperature (affects all chemical reactions and as temperatures increase the reaction of photosynthesis speeds up)
  • carbon dioxide (plants need carbon dioxide to make glucose)
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  • carbon dioxide + water -----> glucose + oxygen
    Leaf adaptations:
  • have large surface area
  • contains chlorophyll in the chloroplast to absorb light
  • air spaces for carbon dioxide
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