genetic diversity Flashcards
what is genetic diversity
number of different alleles in a species or population
name 2 factors that increase genetic diversity
mutations in DNA
different alleles being introduced
genetic diversity allows what to occur
natural selection
what is a genetic bottleneck
causes a big reduction in a population
what does the founder effect describe
when a few organisms start a new colony
describe the steps of natural selection
1- individuals with allele for best survival will survive and reproduce
2- greater number of that allele in population
3- this will be passed on to offspring
what is a behavioural adaptation
ways organisms act that increase their chance of survival and reproduction. eg possums play dead
what is a physiological adaptation
processes in an organisms body that increase chance of survival eg lowering metabolism
what is an anatomical adaptation
structural features of an organisms body that increase chance of survival eg thick layer of fat in wales
what is directional selection
where individuals with an extreme allele are more likely to survive and reproduce
what is an example of directional selection
antibiotic resistance
what is stabilising selection
individuals with middle range characteristics are more likely to survive and reproduce
when does stabilising selection occur
when environment isn’t changing
how does human birth rate show stabilising selection
very small babies less likely to survive
large babies less likely to survive
middle babies is best weight
what is phylogeny
study of evolutionary history of organisms
what is taxonomy
involved naming organisms and organising them into groups
each group in the classification system is called a what
taxa
what is the first taxa organisms are sorted into
domains
name the pneumonic for the classification system
Kingdom
Phylum
Class
Order
Family
Genus
Species
as you move down the taxa of the classification systems what does it mean for relatedness
they get closer related
what is a species
a group of similar organisms able to reproduce to give fertile offspring