Yr9 Biology - Interdependence & Adaptation (GCSE AQA B1.4)

Yr9 Biology - Interdependence & Adaptation (GCSE AQA B1.4)

1. Environmental change

   • Changes in the environment affect the distribution of living organisms
   • Environmental changes can be measured using non-living indicators such as oxygen levels, temperature and rainfall
   • Animals and plants are subjected to environmental changes. Such changes may be caused by living or non-living factors such as 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 sulphur dioxide in the atmosphere
       • lichens found in areas with low levels of sulphur dioxide in the air
     • invertebrate animals can be used as water pollution indicators and are used as indicators of the concentration of dissolved oxygen in water

2. Adaptations

   • To survive and reproduce, organisms require a supply of materials from their surroundings and from the other living organisms there
   • Plants often compete with each other for light and space, and for water and nutrients from the soil
   • Animals often compete with each other for food, mates and territory
   • Organisms, incl. microorganisms have features (adaptations) that enable them to survive in the conditions in which the normally live
   • Some organisms live in environments that are very extreme. Extremophiles may be tolerant to high levels of salt, high temperatures or high pressures
   • Animals and plants may be adapted to cope with specific features of their environment, eg thorns, poisons and warning colours to deter predators
   • Animals and plants may be adapted for survival in the conditions where they normally live, eg deserts, the Arctic
     • Animals may be adapted for survival in dry and arctic environments by means of:
       • changes to surface area
       • thickness of insulating coat
       • amount of body fat
       • camouflage
     • Plants may be adapted to survive in dry environments by means of:
       • changes to surface area, particularly of the leaves
       • water-storage tissues
       • extensive root systems
   • ADAPTATION - a feature or characteristic that allows a living thing to live successfully in its habitat

3. Competition - the rivalry between members of

   • the same species (INTRASPECIFIC), [lion --> lion / humans --> humans], for a resource in limited supply that they both need
   • competition in different species (INTERSPECIFIC), [lions --> hyeena, cheetahs, tigers], for a resource in limited supply that they both need
   • Reduction of other types of competition
     • mating rituals
     • courtship displays
     • features that allow warning fights for dominance

4. Link Between ADAPTATION & COMPETITION

   • If an organism is well adapted to the environment it lives in, it will compete well for limited resources and therefore is more likely to survive and reproduce