B1 SUMMARY NOTES:
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 (binomial) name.
- living things have characteristics that enable them to live in their environment. this is called adaptation.
- members of a species show differences called variation, which can be due to genetics or the environment, and which can be continuous or discontinuous.
- Darwins 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. Genetic 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 are kept constant by…