species and taxonomy Flashcards
- What is the definition of a species?
A group of organisms that are able to produce fertile offspring;
- Describe how breeding experiments could determine whether two populations are from the same species.
Breed the two of the population together; Same species produce fertile offspring; different species will produce hybrids (not fertile offspring).
- Explain why courtship behaviour may be a necessary precursor to successful mating.
It allows them to recognise or attract the same species; It may stimulate the release of gametes; It allows recognition of a mate of the opposite sex; Indicates sexual maturity in a mate; Allows the formation of a pair bond to raise young.
- What is a phylogenetic group?
Organism/species grouped according to evolutionary links and common ancestry;
- What is a hierarchy?
Groups within groups; with no overlap between groups;
- What is a taxon/taxa?
Each group in the phylogenetic classification hierarchy.
- What are the names of the taxa in the most frequently used hierarchy (in order from big to small)?
Domain, kingdom, phylum, class, order, family, genus, species.
- What is the binomial naming system?
Each species is universally identified by the name of its genus and species. Eg. Homo sapiens
- State 3 comparisons of genetic diversity that can be used to compare evolutionary relationships.
The base sequence of DNA; The base sequence of mRNA; The amino acid sequence of proteins;
- Explain how information about amino acid sequence can be used to construct phylogenetic trees.
The amino acid sequence is determined by the DNA base sequence. Those with similar amino acid sequences are more closely related; the greater difference in amino acid sequence the longer ago the groups diverged.
- Suggest how immunology can be used to clarify evolutionary relationships.
A serum from an organism you want to compare is injected into another species. Antibodies specific to this serum are harvested. The specific antibodies are added to serums from other similar species. When the antibodies and antigens form a complex, a precipitate is made. The more precipitate made, the more closely related the species are because their antigens must be similar to the antigens that cause antibody production because they are forming an antibody-antigen complex.
- Explain how a phylogenetic tree diagrams shows evolutionary relationships.
Phylogenetic tree diagrams show points of divergence in history. The modern day species are shown at the ends of the diagram, at the start of the diagram is the most distant common ancestor. The more recent common ancestors are shown as points of divergence close to the modern day species. The further back the point of divergence the more distant the common ancestor is.
