Estimating risk of inherited genetic diseases Flashcards
what is fitness?
the relative ability of organisms to survive to pass on their genes
what is a neutral allele?
an allele that does not affect fitness
what is a deleterious allele?
an allele that decreases an organisms fitness
what is an advantageous alllele?
an allele that increases the fitness of an organism
conditions in which recessive allele affects individual
sickle cell anaemia
thalassaemia
in what type of disorders are De novo mutations common?
dominant
also common in sex linked cases (1/3)
what does the Hardy-Weinburg equilibrium tell us about genotype frequencies over generations?
they remain constant
what are the assumptions underlying the hardy-weinburg equation?
- Mutation can be ignored
- Migration is negligible (No gene flow)
- Mating is random
- No selective pressure
- Population size is large
- Allele frequencies are equal in the sexes
what does mutation do to the proportion of new alleles?
it causes it to increase
what does migration do to the proportion of new alleles
it causes it to increases
what does non-random mating do to levels of mutant alleles/
it causes it to increases
what is assortative mating?
Choosing of partners due to shared characteristics
what is consanguinity?
marriage between close blood relatives
what is a heterozygote advantage?
organisms may be positively selected for if they are heterzygotes of a condition
genetic drift
Random fluctuation of one allele transmitted to high proportion of offspring by chance.
