A-Level Biology AQA Notes

3.4.5 Species and taxonomy

Classification
  • The Biological Species Concept- a species contains all organisms that are capable of breeding together to produce living, fertile offspring.
  • Courtship and mating behaviour are a vital part of species survival. Courtship behaviour enables individuals to: recognise same species members & identify mate capable of breeding
  • Classification is the process of sorting living things into groups.
  • Classification hierarchy comprises the taxa: domain, kingdom, phylum, class, order, family, genus and species.
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  • Classifications are constantly updated as new methods are discovered to infer relationships e.g. DNA sequencing, amino acid sequencing or immunological comparisons.
  • The binomial naming system names species by their genus and species name.
  • Phylogeny is the study of evolutionary relationships between organisms.
  • In a phylogenetic diagram, branch tips represent species at the end of their specific lineage, branching points represent common ancestors & The closer the branches, the closer the evolutionary relationship.
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