Species and taxonomy Flashcards
Definition of classification
The organisation of living organisms into groups. Classification is used to separate animals by their physcial or biochemical properties.
Definition of taxonomy
The study of classification.
Definition of species
A group of similar organisms that can breed together to produce fertile offspring.
What does courtship behaviour ensure?
Mating is successful and the offspring have maximum chance of survival.
Courtship behaviour helps to achieve successful breeding by enabling individuals to…
- Recognise members of their own species.
- Recognise the opposite gender.
- Identify a mate capable of breeding- both partners need to be sexually mature, ferile and receptive to mating.
- Form a pair bond.
- Synchronise mating.
- Stimulates release of gametes.
Definition of hierarchy
Groups within groups, no overlap.
What is the order of the taxonomic ranks?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Definition of phylogeny
The study of evolutionary relationships between species.
What are the three recognised domains?
- Bacteria.
- Archaea.
- Eukarya.
Definition of pylogenetic groups
Grouped according to evolutionary links / history / relationships / common ancestory.
What is a binomial system? Give an example.
Organisms that are identified by two names. Two names come from the genus and the species name, e.g: homo sapiens.
Describe phylogenetic classification
Based on evolutionary relationships between organisms and their ancestors. Arranges the groups into a hierarchy. Evolutionary trees can be created.
Describe evolutionary trees
Used to see how closely species are related, or if any 2 species living today have had a common ancestor at some point in the past. The more closely 2 species are related, the closer they appear together on the evolutionary tree.
How can evolutionary relationships of species be determined?
- Comparing the frequency of observable characteristsics.
- Comparing the base sequence of DNA- the more similar the DNA sequence, the less closely related the 2 species are. Species accumulate mutations over time, so the less closely related they are, the more mutations they will have and therefore the more different the sequences of bases.
- Comparing the base sequence of mRNA.
- Amino acid sequences of certain proteins can be compared between different species- the more similar the amino acid sequence, the more closely related the 2 species are. The more difference in the amino acid sequence, the less closely related the 2 species are.
Describe DNA hybridisation.
Pair two strands for the same gene from two different organisms together. If they are cosely related, the sequence of bases will be very similar so more complementary pairing, so more hydrogen bonds will form. Therefore takes a higher temperature to break these extra bonds.
