Question

Imagine a species with three loci thought to be on the same chromosome. The recombination rate between locus A and locus B is 35%, and the recombination rate between locus B and locus C is 33%. Predict the recombination rate between A and C.

Answer 1

Recombination rate or recombination frequency between locus A and locus C is either 2% or 50%.

Explanation:

As given,

Recombination frequency between locus A and B is 35%, means that the distance between A and B is 35 cM.

Recombination frequency between locus B and C is 33% , means the distance between B and C is 33 cM.

Therefore, if the locus C is present between A and B, then the recombination frequency between A and C would be 2%

A-----C ----------B

A---C= 2%

A----B= 35%

B---C= 33%

So, here the recombination frequency between A and C is 2%, means their distance is 2 cM.

If the locus C is as, A---35---B--33----C ; A-----B------C

A-----B= 35%

B------C= 33%

A-----C= 33+35= 68%

As rule, maximum frequency can not exceed 50%, as here the Recombination frequency between A and C = 50%.