4.5 Species and taxonomy Flashcards
What is a species?
A group of organisms that can interbreed to produce fertile offspring
What are the advantages of courtship behaviour?
Individuals can recognise sexually mature members of their own species of the opposite sex, synchronise mating, form a pair bond and successfully breed
Why does courtship behaviour enable individuals to recognise members of their own species?
to ensure that mating only takes place between members of the same species because only members of the same species can produce fertile offspring
Why does courtship behaviour enable individuals to identify a mate that is capable of breeding?
because both partners need to be sexually mature, fertile and receptive to mating
Why does courtship behaviour enable individuals to form a pair bond?
will lead to successful mating and raising of offspring
Why does courtship behaviour enable individuals to synchronise mating?
so that it takes place when there is the maximum probability of the sperm and egg meeting
Why does courtship behaviour enable individuals to become able to breed?
by bringing a member of the opposite sex into a physiological state that allows breeding to occur
What is classification?
the process of arranging organisms into groups
What are the 2 main forms of biological classification?
- artificial classification
- phylogenetic classification
What is artificial classification?
- divides organisms according to differences that are useful at the time.
- e.g. colour, size, number of legs, leaf shape
What is phylogenetic classification?
the process of arranging organisms into groups based on their evolutionary origins and relationships
What is a taxonomy?
the study of groups and their positions in a hierarchical order
Name the 8 groups of organism can be classified into, from largest to smallest.
domain -> kingdom -> phylum -> class -> order -> family -> genus -> species
What system is used to give species a universal name?
Binomial naming system
What are the 2 components to a binomial name?
Generic name = the genus the organism belongs to. 2 closely related species will share the sane genus
Specific name = the species the organism belongs to
How are binomial names handwritten?
the first letter of the generic name should be capitalised, with the rest in lowercase. The whole name should be underlined
How can we clarify evolutionary relationships between organisms?
Analyse their molecular differences. Advances in immunology/genome sequencing provide clear pictures of how related two organisms are
What is hierarchical classification?
- groups within groups
- no overlap between groups
What are the 3 domains?
- bacteria
- archaea
- eukarya
What are features of bacteria?
- absence of membrane bound organelles such as nuclei or mitochondria
- unicellular
- ribosomes are smaller 70S than in eukaryotes
- cell walls are present and made of murein
- single loop of naked DNA made up of nucleic acids but no histones
How do archaea differ from bacteria?
- their genes and protein synthesis are more similar to eukaryotes
- their membranes contain fatty acid chains attached to glycerol by ether linkage
- there is no murein in their cell walls
- they have a more complex form of RNA polymerase
What are the features of eukarya?
- their cells possess membrane-bound organelles such as mitochondria and chloroplasts
- they have membranes containing fatty acid chains attached to glycerol by ester linkages
- not all possess cells with a cell wall, but where they do it contains no murein
- ribosomes are larger 80S than in bacteria and archaea
What is the eukarya domain divided into?
4 kingdoms:
Protoctista, Fungi, Plantae and Animalia
What is phylogeny?
evolutionary relationship between organisms, reflects the evolutionary branch that led up to it
