4.5 Species and taxonomy Flashcards
How can you tell what organisms are part of the same species (without classification)
- If they belong to the same gene pool (have similar genes)
- Occupy same ecological niche (an organisms role in an ecosystem)
- Using courtship behaviours
What is classification
The process of sorting things into groups
What is taxonomy
The theory and practice of biological classification.
What are 3 reasons why taxonomy is useful
- Accurate identification of unknown species
- Improved understanding of evolution
- Linking of relationships and history between organisms
What are the 2 methods of biological classification
- Artificial classification (old)
- Phylogenetic classification (new)
What is artificial classification
Classifying according to useful/apparent differences/similarities (e.g. putting birds and butterflies in the same group because they can both fly).
Why is artificial classification no longer used
It risks analagous characteristics (share function, but not evolutionary origin).
What is phylogenetic classification
- Classify according to evolutionary relationships between organisms and ancestors
- Usually homologous characteristics (similar origin, regardless of function)
- e.g. presence of nucleus
What is binomial nomenclature and how do you express it
- All organisms identified with 2 names
- 1st name: Genus (capital letter)
- 2nd name: species (lower case)
- type in italics or underline if handrwiting
What are taxa (taxon if singular)
A group of organisms based on phylogenetic classification.
What is the order of taxa
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is the binomial name of a human
Homo sapiens
What are the 3 domains
- Eukarya
- Archaea
- Bacteria
What features of organisms are typically found in the Eukarya domain
- Have membrane-bound organelles
- Membranes contain fatty acids and glycerol
- Do not all possess a cell wall, but when they do it is made from chitin or cellulose
- Have 80s ribosomes
What features of organisms are typically found in the Archaea domain
- Genes and protein synthesis more similar to eukaryotes
- Membranes contain fatty acid chains attached to glycerol
- No murein
- Complex RNA polymerase
What features of organisms are typically found in the Bacteria domain
- No membrane bound organelles
- Unicellular
- 70s ribosomes
- Cell walls made of murein
- Single loop of DNA, no histones
What are the 4 kingdoms in the Eukarya domain
- Animalia
- Plantae
- Fungi
- Protoctista
What are properties of organisms in the protist kingdom
- Complex
- Single celled
- Some multicellular
- e.g. Algae, water molds, slime mold
What are properties of organisms in the fungi kingdom
- Some unicellular
- Most multicellular
- Filamentous forms with specialised complex cells
- e.g. Molds, yeast, mushrooms
What are properties of organisms in the plant kingdom
- Multi cellular
- Have specialised complex cells
- e.g. ferns, woody flowering plants
What are properties of organisms in the animal kingdom
- Multicellular
- Have specialised complex cells
- e.g. invertebrates, birds, mammals
What is phylogeny
The evolutionary relationships between organisms.
What does ‘phylum’ mean
A group of related or similar organisms.
