Population Genetics

Question 1

Hardy-Weinberg Assumptions

Answer 1

1. Organisms are diploid
2. Only sexual reproduction occurs
3. Allele frequencies are equal in both sexes
4. Mating is random
5. No mutation, selection, or migration occurs
6. Generations are non-overlapping
7. Population is infinitely large

Question 2

Linkage Disequilibrium

Answer 2

• Non-random of association of alleles at different loci
• The greater the LD, the more likely two alleles at different loci will be inherited together
• LD shrinks with time, mutation, and migration

Question 3

Inbreeding Coefficient

Answer 3

• F
• Probability that two alleles in an individual are identical by descent

Question 4

Coefficient of kinship

Answer 4

• Phi symbol
• Likelihood that the same allele in two individuals is identical by descent

Question 5

Allelic Heterogeneity

Answer 5

• Multiple alleles on one gene can cause the same phenotype
• Ex. Cystic fibrosis
  
  • DeltaF508 is not the only allele that can lead to disease

Question 6

Locus Heterogeneity

Answer 6

• Multiple genes can cause the same phenotype
• Ex. Fanconi anemia
  
  • Biallelic inheritance of BRCA2, BRIP1, and PALB2 all lead to FA

Question 7

Phenotypic Heterogeneity

Answer 7

• Pleiotropy
• One gene or allele can lead to multiple phenotypes
• Ex. RET gene mutations
  
  • MEN2A, MEN2B, FMTC, Hirshprung’s disease