Population Genetics

Question 0

Gene frequencies

Answer 0

Describes genetic constitution of a population

Question 1

Population

Answer 1

Breeding group or gene pool

Question 2

Frequency of all alleles at any one locus must add up

Answer 2

p+q=1

p and q are frequencies of one and another allele

Question 3

Genotypes must also add up

Answer 3

P+H+Q=1

P=homozygous for one allele
Q=homozygous for other allele
H=heterozygous

Question 4

Frequency in hardy-Weinberg equilibrium

Answer 4

p^2+2pq+q^2=1

Most often use is to determine heterozygote frequency from recessive birth rate

Question 5

For disease causing alleles (q), expect many more heteozygotes than homozygous

Answer 5

2pq»q^2

Question 6

Ratio of carrier to autosomal recessive affected individuals

Answer 6

Great ratio the more rare the disease, makes it harder to remove disease alleles because in carriers

Question 7

X-linked recessive traits

Answer 7

Derive female heterozygous frequency from male birth rate (q) because male has only one X
Use p=1-q (round it!)
Then 2pq for heterozygous female

Question 8

Hardy-Weinberg assumptions

Answer 8

Population large
Allele frequencies remain constant over time
Random mating

Question 9

Exceptions to random mating

Answer 9

Assortative mating (similar phenotype/genotype mate with each other, race, ethnic, consanguinity, etc)
Founder effect, bottle neck effect (smaller population size)
Genetic drift and migration
Race, ethnic background

Question 10

Mutation

Answer 10

Alter allele frequencies very slowly

u=n/2N

u=mutation rate
n=number of affected patients born to unaffected parents
N=total number of births