D.melanogaster question

[Dawid]

Hello everyone!

 

I have one question that I found a bit difficult, could you help me? Here it is- We're crossing white-eye female of D. melanogaster and a wild type male and the offspring is white-eye females and red-eye males. The question is how to explain the result. I was wondering if it can be because of different then 1( X:A) ratio. For example, if the ratio is 1.5 we have a Metafemale with 3 chromosomes X. Is there any possibility that on this additional chromosome we have red eyes gene allel which is then forming a red-eye males? I hope I wrote everything clearly