SectionIIH

Question 1

How is the distance of to genes relate to their recombination frequency?

Answer 1

The further two genes are from eachother, the more they participate in recombination.

• explained by cM measurement.
• 1cM= 1% recombination
• further the genes are from eachtoher the more often they recombine

Question 2

Loci are said to be linked if they experience recombination how often?

Answer 2

-less than 50% of the time.

Question 3

LOD score of what suggests linkage? No Linkage?

Answer 3

• linkage= LOD>3.0
• No Linkage= LOD<-2

Question 4

What is the importance of highly polymorphic DNA markers in gene mapping?

Answer 4

• a high degree of polymorphism ensures that most parents will be heterozygous for the marker locus
• this makes it easier to establish linkage phase in families.

Question 5

What is uninformative mating?

Answer 5

• When some markers are found on both chromosomes or do not carry through a subsequent generation
• does not yeil more information on linkage

Question 6

What is linkage disequallibrium?

Answer 6

• based on the concept that alleles are contantly being recombined and will separate the mutation from the marker over time.
• amount of separation helps to date or age the mutation.

Question 7

What is linkage equillibrium?

Answer 7

• In time, the linkages between a mutation and a marker will reach equallibrium.
• this happens over time as recombination separates the mutation from the marker and others fall into equillibrium.
• moral: the marker used in a young mutation linkage may not be the same as an older mutation due to linkage equallibrium