Question

Problem 2: Silkmoths (4 points, 2 points for each question; please show your work for partial credit) In silkmoths (Bombyx mori), red eyes and white-banded wing are encoded by mutant alleles that are recessive to those that produce wild-type traits. These two genes are on the same chromosome. A moth homozygous for red eyes and white-banded wings is crossed with a moth homozygous for the wild-type traits. The F1 have normal eyes and normal wings. The F1 are crossed with moths that have red eyes and white-banded wings in a testcross. The progeny of this testcross are:

Answer 1

Answer: 50% ErWw (wild-type traits)  and 50% rrww (red eyes, white-banded wings)

To solve this, we need to analyze step by step all the data they give us.

First, they told you about two homozygous traits that are recessive in this kind of animal, Red eyes and withe-banded wings.

We'll assign the names rr and ww (lower because they are recessive)

You know the dominant traits are wild type and all are in the same chromosome.

EE will be normal eyes, and WW  will be normal wings.

If you cross this F0, rrww x EERR  all the offspring are ErWw.

Crossing F1 with red eyes, with-banded wing you have to draw a Punnte square with ErWw x rrww and the ofsspring posibilities you'll find are 50% ErWw (wild-type traits)  and 50% rrww (red eyes, white-banded wings)