In this chapter we study communities, environments, adaptations, and competition. There are a number of ecological terms including community, population, habitat, ecosystem, abiotic factor, and biotic factor, and you need to recall the precise meaning of each.

In studying organisms in their environments, you need to recall the effects of abiotic and biotic factors on populations. You should link this with the importance of temperature and pH on the action of enzymes in B3 Organisation and the digestive system. You will measure the distribution of organisms with quadrats and transects, and carry out a practical to investigate the population size of a common species in a habitat.

We also study competition in animals and plants and you should recall what factors they compete for and how they compete, and how they become successful in their environments. You need to understand how organisms are adapted to survive in many different conditions. In studying animals in cold climates you should make the link to surface area to volume ratio in our work on diffusion in B1 Cells and organisation.

Specification links:

• Set 1 : sections 4.7.1.1 - 4.7.2.1

• Set 2&3: sections 4.7.1.1 - 4.7.2.1

Task 1b: Listen to the podcast to get an overview of this topic

Task 2b: Make notes that:

• Define the following:

  • community,

  • interdependence,

  • population,

  • ecosystem,

  • habitat,

  • abiotic factors,

  • biotic factors.

• Explain how within a community species are interdependent.

• Name 4 examples of abiotic factors.

• Name 4 examples of biotic factors.

Task 3b: Make notes that:

• Define abundance and distribution.

• Name the two sampling techniques.

• Describe the method for investigating population size by random sampling.

• Describe the method of investigating the effect of a factor on plant distribution using a transect line.

Task 5b: Make notes that:

• Define an extremophile.

• Name the 3 types of adaptations in animals.

• Give an example of the 3 adaptations in animals.

• Describe how animals are adapted to hot and cold climates.

• Explain why plants need adaptations.

• Describe how plants are adapted to reduce water loss.

Task 7: Complete the quiz for your set to make sure you understand this unit.