The mouse autosomal genes C and D are linked and 26 map units apart. A CCDD mous
ID: 74135 • Letter: T
Question
The mouse autosomal genes C and D are linked and 26 map units apart. A CCDD mouse is crossed to a ccdd mouse and the F1 progeny crossed to ccdd mice. The proportion of CcDd mice in the testcross progeny will be: a. 0.37 b. 0.26 c. 0.41 d. 0.5 e. 0.13Answer is a, but how to get it? The mouse autosomal genes C and D are linked and 26 map units apart. A CCDD mouse is crossed to a ccdd mouse and the F1 progeny crossed to ccdd mice. The proportion of CcDd mice in the testcross progeny will be: a. 0.37 b. 0.26 c. 0.41 d. 0.5 e. 0.13
Answer is a, but how to get it?
Answer is a, but how to get it?
Explanation / Answer
If the genes C and D are 26 map units apart, when CCDD is crossed with ccdd it results in CcDd.
So the progeny, in this case 26 percent are recombinant then 74 percent should be parental population.
When this CcDd is crossed with ccdd then it produces genotype:
CcDd, Ccdd, ccDd, ccdd
hence in the test cross when CcDc is crossed with ccdd. the CcDc should represent 1/2 of the parentals or 37 percent or 0.37. hence the answer.