Year 12 Biology Help! Genectics, test crosses, autosome & X chromosome?

Question

When looking at Drosophilia melanogaster (vinegar fly) around the compost bin you came across a male and female with yellow eyes. Most of the flies have wild type (red) eyes. Suppose you didnt know whether this gene was on an autosome or the X chromosome. What crosses would you preform to work this out?

Answer 1

First, get a pure-breeding red-eye female.

Then you can cross the yellow male with the red female.  If any males have yellow eyes, then you'd know it was an autosomal mutation.

Answer 2

all i know is the punette square....