B1.4 - Independence and adaptation

• To survive and reproduce, organisms need a supply of materials from their surroundings and from other living organisms
• Organisms have adaptations that enable them to survive in the conditions in which they normally live
• Some organisms live in environments that are very extreme such as extremophiles which can be tolerant to high levels of salt, extreme temperatures or high pressures

Adaptations:

• Animals that are adapted for cold evironments are often large with a small surface area:volume ratio. They have thick insulating layers of fat and fur
• Animals that are adapted for hot, dry environments often include a large surface area:volume ration, thin fur, little body fat and behaviour patterns that avoid the heat of the day

Competition:

• Animals often compete with each other for food, territories and mates
• Animals have adaptations that make them good competitors

Adaptations:

• Plants lose water vapour from the surface of their leaves
• Plant adaptations for surviving in dry conditions include reducing the surface area of the leaves, having water-storage tissues and having extensive root systems

Competition:

• Plants often compete with each other for light, space and water and nutrients (minerals) from the soil
• Plants have many adaptations that make them good competitors

• Changes in the environment affect the distribution of living organisms
• Animals and plants are subjected to environmental changes which may be caused by living or non-living factors such as a change in a competitor, or in the average temperature or rainfall
• Living organisms can be used as indicators of pollution:
  • Lichens can be used as air pollution indicators, particularly of the concentration of sulfur dioxide in the atmosphere
  • Invertebrate animals can be used as water pollution indictators and and used as indicators of the concentration of dissolved oxygen in water
• Environmental changes can be measured using non-living indicators such as oxygen levels, temperature and rainfall