Genes A B and C are linked on a chromosome and found in the

Genes A, B, and C are linked on a chromosome and found in the order A-B-C. Genes A and Brecombine with a frequency of 9%, and genes Band C recombine at a frequency of 23%. For the cross a ⁺b ⁺c/abc⁺ × abc/abc,
predict the frequency of progeny. Assume interference is zero.

1. Predict the frequency of a⁺b⁺c progeny.

2. Predict the frequency of  abc⁺progeny.

3. Predict the frequency of a⁺bc⁺progeny.

4. Predict the frequency of ab⁺c progeny.

5. Predict the frequency of a⁺b⁺c⁺  progeny.

6. Predict the frequency of abc progeny.

7. Predict the frequency of a⁺bc progeny.

8. Predict the frequency of ab⁺c⁺progeny.

Solution

1)27%, frequency of a+b+c will be 27% because b and c together will be 23% and a alone will be 4.5% which is taken as 4%

2)27%= Again the projeny includes all a,b and c genes

3)27% . Here it will be 23 + 4.5%

4)27%. Smae here which will be 23 + 4.5%

5) 59.3% , Here it is sum of all genes and its progeny which is double of 32%

6) 59.3% Again double of 32%

7) 10%

8) 10%