Question

Morgan crossed true breeding red eye (W+), Long leg (SL+) females with true breeding white eye (w), short leg (sl) males. F1 females from this cross were then backcrossed to true breeding white eye (w), short leg (sl) males.

From this cross the following flies were collected:
348 white eye (w), short leg (sl) flies
356 red eye (W+), Long Leg (SL+) flies
68 white eye (w), Long Leg (SL+) flies
55 red eye (W+), short leg (sl) flies
How far apart are the red eye and long leg genes on the X chromosome? (Display your answer in centimorgans, to 2 decimal places.

Answer 1

The F1 parents is : W+ SL+/ w sl

The genetic distance is calculated by the(recombinat/total) × 100 = {(68+55) /(68+55+348+356) }×100= (133/837) ×100= 15.89 cM.

Here recombinat are lower in number and parental are greater in number.

15. 89 is the right answer.