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In Drosophila melanogaster, white eyes (w) is an X-linked recessive mutation. No

ID: 271343 • Letter: I

Question

In Drosophila melanogaster, white eyes (w) is an X-linked recessive mutation. Normal eyes are red (W). At the autosomal wing shape locus, normal shaped wings (Vg) are dominant to vestigial wings (vg). The following cross was made:

XwXw Vgvg x XWY vgvg

What proportion of the progeny from this cross will be males with white eyes and vestigial wings? Write your answer as a numerical value rounded properly to 4 decimal digits. Do not write the answer as a fraction or percentage.

Answer: _______________

Explanation / Answer

Punnett square for the cross between XwXw Vgvg x XWY vgvg is as follows:

From the Punnett square the proportion of the progeny that will be males with white eyes and vestigeal wings (XwYvgvg) is 4/16 = 1/4 = 0.2500.

XWvg XWvg Yvg Yvg XwVg XWXwVgvg XWXwVgvg XwYVgvg XwYVgvg XwVg XWXwVgvg XWXwVgvg XwYVgvg XwYVgvg Xwvg XWXwvgvg XWXwvgvg XwYvgvg XwYvgvg Xwvg XWXwvgvg XWXwvgvg XwYvgvg XwYvgvg