Question

The recombination frequency between genes A and B is 4%. The recombination frequency between genes B and C is 17.3%. If in a progeny of 1926, only 6 double crossovers have been observed, what is the coefficient of coincidence?______ And the interference?______

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Answer 1

Answer-

According to the given question-

Here we have three genes namely A, B and C and they are arranged as in same order as ABC . The recombination frequency between genes A and B is 4% which means that the distance between A and B = 4 cM or map unit.

.While the recombination frequency between genes B and C is 17.3% which means that the distance between B and C = 17.3 cM or map unit .

Total number of progeny= 1926,

Number of double crossovers = 6

We know that

coefficient of coincidence = total number of double crossovers / (distance between first two genes) (distance between last two genes) total number of progeny

= 6 / (0.04) (0.173) 1926

= 6 / 13.327

Coefficient of coincidence = 0.45

Interference (I) = 1 - coefficient of coincidence

= 1- 0.45

Interference (I) = 0.55 or 55 %.