B1.4 Interdependence and Adaptation

  • Created by: Fiona S
  • Created on: 04-06-15 20:29

Organisms are well advised to survive in their normal environments. Population size depends on variety of factors including competition, predation, disease and human influences. Changes in the environment may affect the distribution and behaviour of organisms.

Survival and Competition


  • To survive, organisms require a supply of materials from their surroundings and from the other living organisms there
  • Organisms live, grow and reproduce in places where, and at times when , conditions are suitable


Animals often compete with eachother for:

  • Food
  • Mates
  • Territory

Plants often compete with eachother for:

  • Light
  • Water from the soil
  • Nutrients from the soil


  • Organisms have features (adaptations) which enable them to survive in the conditions in which they normally live
  • The organisms that are best adapted to make use of their resources in a habitat are more likely to survive and increase in numbers

For example:

  • To be able to obtain a certain food better
  • To make it more difficult for predators to catch them
  • To survive in extreme climates, e.g. the artic or deserts
    - Plants lose water vapour from the surface of their leaves
    - It is essential that they have adaptations which minimise this

Extreme Adaptations

  • Extremophiles are organisms that live in extreme environments
  • Some may be tolerent to high levels of salt, high temperature or high pressures
  • Animals and Plants may be adapted to cope with specific features of their environments e.g. thorns, poisons and warning colours to deter predators

Extreme Animals

Animals may be adapted for survival in dry and artic environment by means of:

  • changes to surface area
  • thickness of insulating coat
  • amount of body fat
  • camouflage

Extreme Animals

Example - Camel

  • The camel can go without food and water for 3 to 4 days
  • Fat stored in their humps provides long term food reserve, and a supply of metabolic water
  • The fat is not distributed around the body; this reduces insulation, allowing more heat loss
  • They are tall and thin, increasing their surface area to volume ratio, increasing heat loss by radiation

Example - Polar Bear

  • Polar bear has thick fur and fat beneath its skin to insulate it 
  • Their large, furry feet help them distribute their…


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