I REALLY need help with this punnet square problem thanks

Question

Draw a punnet square to predict the diff. types of offspring that would be produced when a bw-/bw- female is mated to a st-/st- male.

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*I don't understand how I would set this up ... please help me thanks!!!!

the / signs are confusing me ...

Answer 1

You need to give more information as what traits bw and st refer to.

Answer 2

The / sign is just separting the two different alleles.  In this example, you have a female who is homozygous for the bw- allele, meaning she has two copies of it.  The male is homozygous for the st- allele.

But, these are two different genes for eye color:  brown and scarlet.  So, I think you are supposed to assume the flies are homozygous dominant for the other gene.  

That would make the female:  SSbw-bw-

And the male:  st-st-BB

So, the female can only make Sbw- gametes and the male can only make st- B gametes.

The punnett square would look like:

_______Sbw-_______Sbw-

st-B___Sst-Bbw-___Sst-Bbw-

st-B___Sst-Bbw-___Sst-Bbw-

So, all the offspring would be heterozygous for both genes and would show the wild-type eye color because they would have a functioning allele for each gene.