Three loci R, B and Z are located on the same chromosome in this order. The freq

Question

Three loci R, B and Z are located on the same chromosome in this order. The frequency of recombinants between R and B is 20% and the frequency of recombinants between B and Z is also 20%. Assume that crossing over occurs randomly on the chromosome.

a. What is the expected frequency of single recombinants between R and Z?

Please enter your answer as a decimal, rounded to the nearest hundredth, like this: "0.XX", where each X represents a number.

ANSWER: ____________________________

What is the expected frequency of double recombinants between R and Z?

Please use the same format as your previous answer.

ANSWER: ____________________________

Explanation / Answer

a. What is the expected frequency of single recombinants between R and Z?
Please enter your answer as a decimal, rounded to the nearest hundredth, like this: "0.XX", where each X represents a number.
ANSWER: 0.16+0.16 = 0.32

What is the expected frequency of double recombinants between R and Z?
Please use the same format as your previous answer.
ANSWER: 0.04

For explanation find the below workout...

1. Calculation of DCO from COC
2. Calculation of SCO and

1. Calculation of DCO freequency : (E2)
As the interference or COC is not mentioned here, condiering that the interference is 0, hence the
COC = 1 (because COC + I = 1).
COC = Prop of ODCO/ Prop of EDCO.
=> 1 = Prof of ODCO/ (20/100 X 20/100) => DCO = 1 X 0.20 X 0.20 = 0.04

The Freequency of DCO = 0.04

2. Calculation of SCO:. (E1)
The Distiance between two genes= Prop of SCO+ Prop of DCO.
So, Prop of SCO = Distiance between two genes - Prop of DCO.

Between first pair of genes =
The Distance = 20, The proportion = 20/100 = 0.20
Prop of SCO = 0.20- 0.04 = 0.16

Between second pair of genes =
The Distance = 20, The proportion = 20/100 = 0.20
Prop of SCO = 0.20- 0.04 = 0.16

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