Lectures 10-12 - Linkage Recombination And Mapping

Question 1

Linkage?

Answer 1

Genes are on the same chromosome

Question 2

Recombination?

Answer 2

Infrequent exchange between chromosomes of genes

Question 3

What is the frequency of recombination formula?

Answer 3

Freq of recomb = total recombinant/ total number of offspring

Question 4

When does homologous recombination occur?

Answer 4

Prophase 1 of meiosis

Question 5

How does distance impact recombination?

Answer 5

Closer genes are on the chromosome, the more likely they are to crossover together - less recombinants
Further genes on chromosome are less likely to cross over together - more recombination

Question 6

Recombination frequency and map units?

Answer 6

Recombination frequency is equal to map units cM

Question 7

What are the three scenarios for a dihybrid cross?

Answer 7

1) genes a and b are independently assorting - 9:3:3:1
2) genes a and b are tightly linked so that crossing over does not happen - 3:1
3) genes a and b are linked so crossing over does occur -variations

Question 8

The recombination frequency and map distance relationship?

Answer 8

As recomb frequency increases, map distance increases, but at 50cM, map distance cannot increase anymore

Question 9

What is trans configuration? (Coupling)

Answer 9

Homozygous linked

Question 10

What is trans configuration?

Answer 10

Heterozygous linked