Introduction to Genetic Variation

Question 1

What are single nucleotide polymorphisms?

Answer 1

A single base substitution occurring across the genome

Question 2

What are Haplotypes and Genotypes?

Answer 2

Haplotypes - series of SNP alleles along single chromosomes

Genotypes - two alleles present at a SNP in an individual

Question 3

What is a linkage disequilibrium?

Answer 3

SNP’s in some regions may be correlated

if SNP 1 and 2 were in a LD then allele at SNP1 gives information to an allele and SNP2

Question 4

What is the Hardy-Weinberg principle?

Answer 4

It explains the stability of allele and genotype frequencies across generations
1=p2+2pq+q2 
p+q=1
Frequency of alleles A = p+1/2q
Frequency of alleles B = q+1/2p

Question 5

What requirements must be met for the Hardy-Weinberg principle?

Answer 5

Large population, no migration, no new mutation, no selection and random mating