Classification, Variation and Inheritance
- Living things are put into groups according to how closely they are related to one another. The Kingdom is the largest group and species the smallest. Each species is given a two-part (binomal) name.
- Living things have characteristics that enable them to live in their environment. This is called adaptation .
- Members of species show differences called variation, which can be due to genetics or the environment, and which can be continuous or discontinuous.
- Darwin's theory of natural selection explains how living things evolved due to variation and survival of the best-adapted.
- Alternative forms of genes called alleles are passed from parents to offspring. A dominant allele masks the presence of a recessive allele.
- Disorders such as sickle cell disease and cystic fibrosis are inherited. Gentic diagrams help us to analyse who in a family is at risk of having the disorder or being a carrier of the affected allele.
Responses to a Changing Environment
- The amount of water and glucose in the body and body temperature and kept constant…