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What you need to know

Reflections and Exam tips


Adapt and survive

To adapt is to change and suite the present conditions. If you don't, you will soon be outdated and become extinct!

As the environment keeps changing, plants and animals need to keep changing to fit.

What organisms need/compete for?

What animals need:

  • Food
  • Shelter
  • water
  • Mates
  • Territory
  • Oxygen

What plants need:

  • Space
  • Water
  • carbon dioxide
  • Sunlight
  • Nutrients from the soil (N, P, K, Mg)

Both animals and plants need to adapt to compete successfuly for these requirements.

There is growing interest in organisms that can survive in extreme environments, for example: very low temperatures of Antarctica, very hot deserts environments and very acidic or alkaline environments. These organisms are called extremophiles.


Animal adaptations

Animals have physical and behaviour adaptations to get these requirements that we outlined above. These include:

  • Thick fur
  • Hollow fur
  • Blubber
  • Camouflage
  • Sharp teeth and claws
  • Ability to run very fast
  • Ability to mimic/imitate other animals


Plant adaptations

These include:

  • Thick, waxy cuticle
  • Few stomata
  • Sunken stomata
  • Hairs and
  • Spikes/thornes
  • Broad (wide) leaves
  • Thin leaves
  • Green stem
  • Short stems and leaves that just lie flat on the ground
  • Deep roots
  • Shallow roots

Environmental change and survival

Organisms need to be able to change to fit in with the changing environment. Failure to do so may result in extinction. So organisms may have to change:

  • Their behaviour
  • Their type of food
  • Reproductive seasons and patterns
  • Their habitat- migrate elsewhere

Pollution indicators

Living organisms (both plants and animals) are sensitive to even minor changes in their surroundings such as pH, types of gases in the air etc. The major changes involve:

Chemicals in water

  • Amount of sulphur dioxide in the air- leading to acidification of water.
  • Nitrates in water.
  • Concentration of oxygen in the water.

These organisms may be used as indicators of pollution as they respond to these pollutants. They include:

  • Mayfly lavae in water
  • Bloodworms in water
  • Lichens on tree trunks, rocks and buildings
  • Moss on roofs of houses and on dead tree trunks.

Measuring environmental change

Some scientists spend their lives measuring changes in these pollutants so as to inform decision making and environmental policies. The things that they can measure include:

  • Oxygen concentrations in water- using oxygen meters
  • Levels of carbon dioxide in the air- Carbon dioxide meters
  • Concentrations of Nitrates in water
  • Levels of light- light meters
  • pH of water- pH meters















Why do you think scientists are interested in extremophiles?




For each of these adaptations, name an organism and identify its environment.