EE3 Flashcards
What are most mutations?
What is most genetic variation?
Selectively Neutral
Neutral
How did Watson and Crick discover the structure of DNA?
By stealing Franklins xray defraction of DNA.
What is a polymorphism?
When two or more distinct phenotypes exist.
What is an SNP
Single Nucleotide Polymorphism
- can be due to indels, base swaps
What is a Synonamous mutation?
A mutation that doesnt change the AA
What is Non-synonamous mutation?
A mutation that changes the AA
What is the Neutral Theory of Molecular Evolution?
The neutral theory states that the observed genetic variation is greater than would be predicted by natural selection. And that most variation and evolutionary changes in species is caused not by Natural selection but by random drift of mutant alleles. It is neutral.
When is the mutation drift equilibrium reached?
When new mutations balance diversity lost to drift.
How does the likelihood of and time to fixicity of an allele change with population size?
Time to fixation is slower in larger populations
small popualtions fix a higher proportion
Substitution rate=
mutation rate. (mu)
Mutations per site per generation is 2 times the allele frq time the mutation rate.
the probability it will be fixed is 1/2 and allele frequency
Substituion rate is tehrefore 2Nemu x 1/2Ne = mu
Sickle Cell Anaemia
- Heomoglobin protein
- Base substution = Glu- Val 7
= polar uncharged to hydrophobic - makes sickle shape
Duchens Muscular Dystrophy
- dystrophen on x chromosome mutatation makes a premature stop codon loss of gene function 1/3500 males muscle waste and death
CCR5
Chemokine receptor type 5
It is a transmembrane protein that HIV-1 requires to enter the cell
CCR5-Delta-32 is a bp deletion which stops gene funtion.
CCR5-delta-32 homozygotes are resistant to HIV
