3.4.5 Species + Taxonomy Flashcards
What’s phylogeny
The study of the evolutionary history of groups of organisms
Tells us who’s related to who + how closely related they are
What can be shown in a phylogenetic tree/system
That all organisms have evolved from shared common ancestors (relatives)
What a phylogenic system
Grouping organisms bases on them evolutionary relationships between organisms + their ancestors
What’s taxonomy
The theory + practice of biological classification
It involves naming organisms + organising them into groups
How many levels of groups are used to classify organisms
What are these called
8
Taxa (a taxon)
What are the positions within taxonomy called
Taxonomic ranks
What are the groups arranged in
A hierarchy with the largest organisms at the top and smallest at the bottom
What’s a hierarchy
A layered system with no overlaps
Groups within groups
What’s artificial classification
Grouping organisms according to differences that are useful at the time e.g colour, number of legs, leaf shape
What system is still used today
The Linnaean system
What’s the Linnaean system in order
Domain
Kingdom Phylum Class Order Family Genus Species
What’s the plural of genus
Genera
What part of the Linnaean system is as a capital letter
Genus
What part of the Linnaean system is as a lower case letter
Species
How is a cladogram set out
Oldest species at base of tree
Most recent species at ends of branches
Closer branches - closer evolutionary relationship
What are the 3 domains (biggest)
Bacteria
Archaea
Eukarya
What are bacteria
Unicellular prokaryotes
4 factors of bacteria
- Don’t have nucleus/mitochondria (no membrane bound organelles)
- small ribosomes (70s)
- murein cell walls
- single loop of naked dna, made up of nucleic acids but no histones
- no introns
What are archaea
Unicellular prokaryotes that resemble bacteria
3 ways archaea differ to bacteria
- genes+ protein synthesis more similar to eukaryotes
- membranes contain fatty acid chains attached to glycerol by Ester bonds
- no murein cell walls
- more complex rna polymerase
What’s eukarya like
Multicellular
4 factors of eukarya
- have membrane-bound organelles (nucleus + mitochondria)
- membranes contain fatty acid chains attached to glycerol by Ester bonds
- don’t all posses a cell wall, but wouldn’t contain murein
- larger ribosomes (80s)
How many kingdoms does the eukarya domain have
What are they
4
- Proctoctista
- Fungi
- Plantae
- Animalia
What’s the bionomial naming system
Describe it
E.g
The nomenclature (naming system) used for classification
All organisms are given 1 accepted scientific Latin name with 2 parts to it
1st part- genus (capital letter)
2nd part - species (lower case)
E.g humans - Homo sapiens
What is courtship behaviour carried out by organisms for
To attract a mate of the right species
E.g of simple courtship behaviour + complex courtship behaviour
Simple - releasing chemicals
Complex - series of displays
How does courtship behaviour make reproduction more successful in a species
As it’s species specific
Allowing members of same species to recognise each other, preventing interbreeding
What can courtship behaviour be useful to us for
Classifying organisms
What does a more similar courtship behaviour tell us about organisms
They’re more closely related
Define a species
Group of similar organisms able to reproduce to give fertile offspring
