Mod 6 Flashcards
Genetic drift
Random change in frequency of alleles over time - due to genetic variation when creating gametes
DUE TO CHANCE some alleles maybe lost some may increase in frequency
Small vs larger populations
Impact smaller populations more - rare alleles are more likely to be lost ; genetic diversity usually decreases
Genetic bottleneck
Decreases reduction in population size - gene pool decreases - decreases chance of survival against disease for example
Remaining individuals very similar genes - higher impact from genetic drift
Reduced variation
Founder effect
New population formed means smaller number of alleles from initial gene pool - will grow with reduced genetic variation and more influenced by genetic drift
Allopatric speciation
Geographically isolated
Separates original population into two - unable to reproduce due to geographical barrier
Continue to accumulate different mutations to help them survive their environment ; over time so genetically different unable to interbreed to produce fertile offspring
Sympatric speciation
Differences in behaviour ; random mutation may impact reproductive behaviour - no gene flow between groups within the populations
Over time reproductively isolated populations accumulate different mutations - cannot interbreed to create fertile offspring
Evolution happens quickly
In smaller populations
In a small population
A small number of alleles changing has a bigger impact
Genetic bottlenecks
Almost all of population is wiped out - many alleles for genes are lost and remaining population passes on the same alleles - lack of genetic diversity and thus genetic diseases that exist in population are far more likely to be passed on
Natural selection
Always begins with a wide range of variation due to genetic and environmental factors
Primary source or genetic variation is mutation
Predation/disease/competition result in selection pressures
Selective advantage are likely to survive and reproduce more offspring/pass on their favourable alleles to the next generation - changes allele frequency
Artificial selection
Humans SELECT plants/animals with favourable characteristics and deliberately breed them together ; manipulates gene pool so favourable alleles = more common
Ethical issues with pugs
Promoter region of DNA?
Region where RNA polymerase binds to begin transcribing a gene
Intracellular
Catalase and lactase
Types of adaptations
Behavioural
Physiological - body process
Anatomical - feature on an irganism’s body
Why does non coding region show more variation?
This doesn’t affect survival - coding regions DO affect survival
