Ecology Flashcards
Describe the process of natural selection
1) Characteristic due to mutation
2) Characteristic provides advantage
3) Individuals with characteristic more likely to survive and reproduce
4) Directional/Stabilising selection
5) Frequency of allele increases in subsequent generations
What is directional selection?
When a phenotype is favoured over other phenotypes, causing that allele to become more frequent over time
What is stabilising selection?
When the population mean stabilises and tends towards the average
Aseptic technique
1) Wash hands to remove/kill microbes
2) Burning Bunsen close by to create upward current of air
3) Disinfect workplace
4) Flame instruments used to sterilise
5) Lift lid slightly (on agar plates) to prevent entry of microbes
Mutations and evolutionary relationships
1) Mutations change base/nucleotide sequence
2) Causing change in amino acid sequence
3) Mutations build up over time
4) More mutations between distantly related species
5) Distantly related species have earlier common ancestor. Closely related species have recent common ancestor
Methods of measuring genetic diversity
1) Comparing measurable/observable characteristics
2) Comparing amino acid sequences/primary structures of a named/same protein
3) Comparing difference in the base sequence of DNA
4) Comparing differences in the base sequence of mRNA
Importance of courtship behaviour
1) Recognise/identify/attract same species
2) Stimulates release of gametes
3) Recognition of opposite sex
4) Indication of sexual maturity
5) Formation of a bond between two organisms
What are the taxa?
Kingdom, phylum, class, order, family, genus, species
Hierarchy
1) Groups within groups
2) No overlaps between groups
What is phylogeny?
Grouped according to evolutionary links/history/relationships/common ancestry
What defines a species?
Ability to reproduce and produce fertile offspring
What is species richness?
A measure of the number of different species in a community
