CGC Population Genetics & Epidemiology

Question 1

Hardy-Weinberg equilibrium requires which of the following conditions?

Accepted Answer

Random mating, no mutation, no migration, no selection, and large population size

Answer

Hardy-Weinberg equilibrium is maintained in large, randomly mating populations free of mutation, migration, and selection pressure.

Question 2

In a population where the frequency of a recessive allele (q) is 0.1, the expected carrier frequency under Hardy-Weinberg equilibrium is:

Accepted Answer

0.18 (18%)

Answer

Carrier frequency = 2pq = 2 × 0.9 × 0.1 = 0.18, meaning 18% of the population are heterozygous carriers.

Question 3

The founder effect in genetics refers to:

Accepted Answer

Reduced genetic diversity in a population descended from a small founding group

Answer

The founder effect occurs when a small isolated group establishes a new population, leading to high frequencies of alleles present in the original founders.

Question 4

Genetic drift is MOST significant in:

Accepted Answer

Small, isolated populations

Answer

Genetic drift causes random fluctuation in allele frequencies that is most pronounced in small populations where chance events have a larger proportional impact.

Question 5

Which term describes the increased frequency of a condition in offspring of consanguineous couples compared with the general population?

Accepted Answer

Autozygosity

Answer

Autozygosity refers to inheriting identical-by-descent alleles from a common ancestor, which increases the risk of homozygosity for recessive pathogenic variants in consanguineous offspring.

CGC - Certified Genetic Counselor Practice Test

CGC - Certified Genetic Counselor Practice Test

CGC Population Genetics & Epidemiology