| Species meaning | - A group of similar organisms able to reproduce to give fertile offspring |
| The binomial naming system | - Nomenclature (naming system) used for classification
- Organisms given 1 internationally accepted scientific name in Latin that has 2 parts |
| First name | - Genus name
- Has capital letter
- Written in italics or underlined |
| Second name | - Species name
- Lower case
- Written in italics or underlined |
| Reason for naming system | - Helps avoid confusion of common names |
| Courtship behaviour | - Carried out by organisms to attract a mate of the right species
- Its species specific, so members of same species can recognise each other
- Prevents inbreeding + more successful reproduction |
| How they achieve courtship | - Recognising members of own species
- Identify a mate that is capable of breeding
- Form a pair bond
- Synchronise mating
- Become able to breed |
| Recognising members of own species | - Ensures that mating only takes place between members of same species
- As only members of same species can form fertile offspring |
| Identify a mate that is capable of breeding | - Both partners need to be sexually mature, fertile + receptive to mating |
| Form a pair bond | - Lead to successful mating + raising of offspring |
| Synchronise mating | - So it takes place when there is the maximum probability of the sperm + egg meeting |
| Become able to breed | - By bringing a member of the opposite sex into a physiological state that allows breeding to occur |
| Classification meaning | - The grouping of organisms |
| Taxonomy meaning | - The theory + practice of biological classification |
| Two main forms of biological classification | - Artificial classification
- Phylogenetic classification |
| Artificial classification | - Organising organisms according to differences that are useful at the time
- Features like colour, size...analogous characteristics |
| Analogous characteristics | - Features that have the same function but do not have the same evolutionary origins e.g. wings |
| Phylogenetic classification | - Based on the evolutionary relationships between organisms + their ancestors
- Classifies species into groups using shared features derived from ancestors
- Arranges groups into hierarchy, no overlap
- Partly based on homologous characteristics |
| Phylogenetic trees | - Shows relationship between members of families
- 1st branch represents common ancestor of all the family members
- Each following branch represents another common ancestor from which a different group diverged
- Closely related species diverged away from each other most recently |
| Taxonomy | - 8 levels of groups to classify them, taxa, each group called taxon
- Arranged in hierarchy, largest groups at top, no overlap
- Divides into smaller groups that are more closely related |
| The 3 groups in the domain | - Eukarya
- Archaea
- Bacteria |
| The taxa | - Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species |
| Eukarya (domain) | - Made up of 1 or more eukaryotic cells
- Has membrane-bound organelles
- Has membranes containing fatty acid chains attached to glycerol by ether linkages
- Not all possess cells with cell wall, but where they do it contains no murein
- Ribosomes larger that archaea + bacteria |
| Archaea (domain) | - Single-celled prokaryotes that were originally classified as bacteria
- Differ from bacteria as their genes + protein synthesis are more similar to eukaryotes
- Membranes contain fatty acid chains attached to glycerol by ether linkages
- No murein in cell walls
- More complex form of RNA polymerase |
| Bacteria (domain) | - A group of single-celled prokaryotes with prokaryotic features |
