Female flies homozygous for gray body blk and red eyes v wer

Female flies homozygous for gray body (blk) and red eyes (v^+), were crossed with male flies with black body (blk) and vermilion eye colour (v). All the F_1 generation had gray bodies and red eyes. The F1 females were testcrossed to black-bodied, vermilion-eyed males. The F2 progeny were sorted by phenotype and counted: 162 gray-bodied, red-eyed flies; 149 black-bodied, vermilion-eyed flies; 77 gray-bodied, vermilion-eyed flies; and 72 black-bodied, red-eyed flies. Calculate the frequency of recombination. (SHOW YOUR WORK)

Solution

The frequency of recombination = {Number of recombinants / ( Number of recombinants + Number of parental types)} * 100 %

Parental types are : gray-bodied , red eyed flies : 162

black-bodied ,vermilion eyed flies:149

Total = 311

Recombinants are : gray-bodied , vermilion eyed flies: 77

black -bodied , red eyed flies : 72

Total = 149

Therefore, frequency of recombination = (149 / 311 +149 )*100%

=32% ( ans)