3.4.4 Genetic diversity and adaptation 3.4.5 Classification and taxonomy

Question 1

What is taxonomy?

Answer 1

The theory and practice of biological classification

Question 2

What is phylogeny?

Answer 2

The evolutionary relationship between organisms

Question 3

What is classification?

Answer 3

The grouping of organisms

Question 4

What is a species?

Answer 4

Can breed
To produce fertile offspring

Question 5

Describe natural classification

Answer 5

• classifies species in a phylogenetic classification system based on shared evolutionary features and evolutionary relationships
• groups arranged into a hierarchy - smaller groups placed within larger groups without overlapping
• each group is called a taxon (pl taxa)

Question 6

What is the sequence of taxa

Answer 6

Domain
Kingdom
Phylum
Class
Order
Family
Genus
species
(Drunk kangaroos punch children on family game shows)

Question 7

What features do species have?

Answer 7

• belong to same gene pool
• similar to each other, different to members of other species
• occupy same ecological niche
• some use courtship to recognise members of the same species

Question 8

What does courtship behavior enable individuals to do?

Answer 8

• attract / recognise members of the same species
• attract / identify a mate that is capable of breeding (sexualy mature)
• synchronise mating / become able to breed - stimulate the release of gametes
• form a pair bond

Question 9

What is the stimulus response chain?

Answer 9

• male carries out an action
• this is a stimulus for the female to respond with a specific action of her own
• her response stimulates male to perform a further action
• ritual continues

Question 10

Describe and explain the process of natural selection

Answer 10

• variation exists in a population
• due to random mutation
• advantageous allele produced
• a named environmental condition creates a selection pressure (eg black bark allows camouflage so not eaten)
• organisms with advantageous named allele
• more likely to survive and reproduce and pass on the allele to offspring
• frequency of allele increases over several generations
• name type of selection - directional or stabalising

Question 11

What is stabilising selection?

Answer 11

• preserves the population characteristics
• selects phenotypes around the population mean and against population extremes
• same mean, lower standard deviation from mean, higher peak
• eg human birth weight

Question 12

What is directional selection?

Answer 12

• changes the population characteristics
• selects for phenotypes at 1 extreme of the population (phenotypes at other extreme lost)
• distribution curve has same shape but mean shifts left or right
• eg antibiotic resistance in bacteria