Linkage 1

Question 1

What is linkage equilibrium

Answer 1

Random association of alleles at two or more loci (LE)

Question 2

What is linkage disequilibrium

Answer 2

Non random association of alleles at 2 or more loci (LD)

Question 3

Is linkage equilibrium the same as linkage

Answer 3

No, linkage can be a reason for linkage disequilibrium

Question 4

How to calculate expected frequencies of chromosomes from observed allele frequencies

Answer 4

If frequency of a is 0.2 and B is 0.3, then aB is 0.2x0.3

Question 5

How is linkage disequilibrium (D) calculated from haplotype

Answer 5

D=(F(AB)xF(ab))-(F(Ab)xF(aB)) (coupling gametes -repulsion gametes)

Question 6

If completely unlinked

Answer 6

D=0

Question 7

If partially linked

Answer 7

D=between 0 and 25

Question 8

If completely linked

Answer 8

D=25 (positive or negative)

Question 9

What do all the frequencies need to sum to

Answer 9

1

Question 10

What happens if there’s dominance

Answer 10

We can’t calculate D unless we know the haplotypes

Question 11

+ means what

Answer 11

Coupling

Question 12

-

Answer 12

Repulsión

Question 13

Expected haplotype frequencies at linkage equilibrium equation then how to test disequilibrium

Answer 13

F (AiBj)=F(Ai)cF(Bj) then chi square test