Question

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

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Answer 1

The coefficient of coincidence is calculated by dividing the actual frequency of double recombinants by this expected frequency: c.o.c. = actual double recombinant frequency / expected double recombinant frequency.

So here expected double reombinent frequency is 6 amd actual double recombinent frequency is 160 (0.80×0.20×1926)

And the coc (coefficient of coincidence ) is = 308.1÷ 6  = 51.36

And the interface = coc - 1 = 51.36 - 1 =50.36.

NOTE: genetic linkage: When genes are on separate chromosomes, or very far apart on the same chromosomes, they assort independently. That is, when the genes go into gametes, the allele received for one gene doesn't affect the allele received for the other. In a double heterozygous organism (AaBb), this results in the formation of all 444 possible types of gametes with equal, or 25\%25%25, percent, frequency.