Biology Autosomal and X-linked genetics problem

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In the discussion about a genetics problem involving Drosophila melanogaster, participants focus on how to approach a cross involving both autosomal and X-linked traits. The traits in question are vestigial wings, which are autosomal and recessive, and white eyes, which are X-linked and also recessive. A suggestion is made to use a Punnett square to visualize the crosses, treating the traits similarly to a dihybrid cross while keeping track of the sex-linked traits. The genotypes of the parents are clarified as homozygous for their respective traits, with the female being WWrr and the male wwRY. Overall, the conversation emphasizes understanding the independent assortment of genes and the importance of correctly interpreting the allelic naming conventions.
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Homework Statement


In the fruit fly drosophila melanogaster, vestigial (partially formed) wings (vg) are recessive to normal long wings (vg+) and the gene for this trait is autosomal. The gene for the white eye trait (w = white is recessive to w+ = red) is located on the X chromosome. Suppose a homozygous white-eyed, long winged female fly is crossed with a homozygous red-eyed, vestigial winged male.

a) What will the genotypes and phenotypes of the F1 flies?

b) What will the genotypes and phenotypes of the F2 flies?

c) What will the genotypes and phenotypes of the the offspring of separate crosses of the F1 flies back to each appropriate parent?



Homework Equations


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The Attempt at a Solution


I know how to deal with autosomal and X linked trait questions individually but I don't know how to solve the question when both autosomal and X linked traits are involved.

Help is appreciated. Thanks
 
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can someone please provide me some hints?
I'm very stressed out about this question.
 
You set up the problem very much the same way as if it were autosomal or x-linked only. Try using a Punnet square to work it out as if it were any other autosomal two-trait cross, but use a symbol for the sex-linked traits that reminds you which chromosome they came from.
 
Moonbear said:
You set up the problem very much the same way as if it were autosomal or x-linked only. Try using a Punnet square to work it out as if it were any other autosomal two-trait cross, but use a symbol for the sex-linked traits that reminds you which chromosome they came from.

Can you give me a few more hints or explanations?
I'm still really confused.
 
help please?
 
If you know how to deal with them individually, you're going to be fine... remember the law of independent assortment?

I think part of the problem is the very strange allelic naming system... the standard is to use the first letter of the dominant trait and for Capital letters to be dominant and lowercase letters to be recessive...
ok other than that I think I can get you started without giving too much away: based on the information in the question I'd wager that the genotypes of the parents are: using W = Long Wing (w = recessive vetigial wing) and R=Red eye (r = recessive white eye) and remember Y=male
we have a white eyes long winged female and we are told it is homozygous so: (WWrr) must be the genotype
and red eyed vestigial winged male (also homozygous) must be (wwRY)
simply do a dihybrid cross from there, and let us know if you need some more help.
 
Last edited:
Thanks for jumping in Oaksinstructor. Sorry for not being able to get back sooner Intr3pid, I was away for a few days for the holiday. Yes, I think the unusual naming convention is causing added confusion...too many letters to get confused.
 

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