Population Genetics

Question 1

What is population genetics?

Answer 1

The study of allele frequencies and changes in allele frequencies in ‘populations’

(= The quantitative study of the distribution of genetic variation in populations and how the frequencies of genes and genotypes are maintained or change)

Question 2

What are the basic principles of population genetics?

Answer 2

• Mutation rates
• Fitness
• Effects of consanguinity
• Addition of new mutations to gene pool

Question 3

What are the necessary assumptions for the Hardy-Weinberg Principle?

Answer 3

• Large population mating randomly
• Allele frequencies remain constant over time because:
o No appreciable rate of new mutation
o No selection for/against any allele
o No appreciable immigration/emigration of persons from population with different
allele frequencies

Question 4

What forces affect allele frequency?

Answer 4

1. Natural selection
2. Genetic drift
3. Mutations
4. Gene flow

Question 5

When reproductive fitness is >0 how are the following accounted for in the calculation of mutation rate?
(1) Autosomal dominant traits
(2) Autosomal recessive traits
(3) X-linked recessive traits
where: 
μ=mutation rate /gene/generation
F=frequency of the disease
f=reproductive fitness

Answer 5

Autosomal dominant: μ= 1/2 F (1-f)

Autosomal recessive μ= F (1-f)

X-linked recessive μ= 1/3 F (1-f)

Question 6

What equation is used to predict the allele and genotype frequencies of the next generation?

Answer 6

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

where:
p = dominant allele
q = minor allele