Genetics question- What results are expected in the F2?

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Genetics question- What results are expected in the F2?

Post by justinbains132 » Wed Mar 03, 2010 12:51 am


I was wondering could any body assist me in doing this question I am having trouble working it out. Thanks alot!

Morgan crossed his white-eyed, grey-bodied female flies with red-eyed, black-bodied male flies. In the F1 all the females had red eyes and grey bodies and all the males had white eyes and grey bodies. What results do you expect in the F2 (after an F1 self cross)? Assume all parental flies are homozygous and that these genes are not on the same chromosome

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Post by JackBean » Wed Mar 03, 2010 3:35 pm

the color of body seems to be quite easy, it's on autosome and black color is reccessive, thus F1 are all heterozygous Gg and in F2 they will be GG : Gg : gg being 1 : 3 grey to black

the color for eyes seem to be sex-related with red being dominant (females have two X). So, the females in F0 were xx, males were XY, so you get xX (female with dominant (red) eye color) and xY (male with reccessive (white) eye color). I hope, the rest will be easy ;)

Cis or trans? That's what matters.

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