POPULATION GENETICS

Question 1

Describe the blending inheritance model.

Answer 1

Offspring will be intermediate, whether parents are of intermediate phenotype or 2 extreme phenotypes. Variance would be reduced in successive generations.

Question 2

What are the 2 steps in analysis of genetic variation?

Answer 2

Describe phenotypic variation, and then translate the phenotypes into genetic terms and describe variation in the genotype.

Question 3

Describe the Hardy-Weinberg Equilibrium.

Answer 3

Random mating results in an equilibrium distribution of genotypes after one generation. This can be altered by inbreeding or other “unbalanced” genetic pressures.
If the alleles at a locus are in Hardy-Weinberg equilibrium within a population, then the frequency at which each allele occurs in the population does not change from one generation to the next.

Question 4

What are 5 forces affecting genetic equilibria?

Answer 4

1. Mutation (and recombination)
2. migration
3. non-random mating
4. natural selection
5. random genetic drift

Question 5

Give an example of departure from Hardy-Weinberg equilibrium.

Answer 5

Assortative mating: selecting a mate on the basis of heritable traits.

Question 6

What are the 3 methods of assessing population variation?

Answer 6

1. phenotype frequency
2. genotype frequency
3. allelic frequency