What is the expected genotypes and phenotypes of F1 flies in the cross between virgin brown eyed female with scarlet males (genes for brown and scarlet eyes are on different autosomes)?

I know that brown eyes and scarlet eyes are both recessive but I'm not sure what he genotype of the parents would be

brown eyes = bw
scarlet eyes = st

What does it mean when the genes are on different autosomes?

An autosome is a chromosome that is not an allosome (i.e., not a sex chromosome). Autosomes appear in pairs whose members have the same form but differ from other pairs in a diploid cell, whereas members of an allosome pair (XX, XY) may differ from one another and thereby determine sex.

Would the parent female genotype be... bw/bw,st+/st+ ? and the male genotype be... bw+/bw+,st/st ?

When the genes for brown eyes (bw) and scarlet eyes (st) are on different autosomes, it means that they are located on separate chromosomes that do not determine sex. In other words, the inheritance of these eye color genes is not linked to the inheritance of sex chromosomes (X and Y).

To determine the expected genotypes and phenotypes of the F1 flies in the cross between a virgin brown-eyed female and scarlet-eyed males, we need to consider the genotypes of the parents.

Since brown eyes and scarlet eyes are both recessive traits, it means that they are only expressed when an individual has two copies of the corresponding recessive gene.

Let's assume that the virgin brown-eyed female has the genotype bb (homozygous recessive for brown eyes). Since brown eyes are recessive, the only possible genotype for a brown-eyed individual is bb.

As for the scarlet-eyed male, we don't know the genotype based on the given information. However, since scarlet eyes are also recessive, the genotype could be either ss (homozygous recessive for scarlet eyes) or Ss (heterozygous with one scarlet allele and one dominant allele).

If we assume that the male is homozygous recessive (ss), then the genotype of the parents would be:

Female (brown eyes): bb
Male (scarlet eyes): ss

Now, let's consider the possible genotypes and phenotypes of the F1 flies resulting from this cross:

When the parents have the genotypes bb (female) and ss (male), all the offspring (F1 generation) will be heterozygous for both traits. This means that the expected genotype for the F1 flies will be BbSs.

However, it's important to note that since we don't know the genotype of the male for sure (whether it is ss or Ss), there is a possibility of different genotypes in the F1 generation. If the male is heterozygous (Ss), then the potential genotypes in the F1 generation would be BbSs and Bbss.

As for the phenotypes, since both brown eyes and scarlet eyes are recessive, the F1 flies will display the dominant eye color phenotype, which is neither brown nor scarlet. The dominant eye color in this case is likely to be a wild-type eye color, such as red eyes.

In summary, the expected genotypes in the F1 flies would be BbSs (if the male is homozygous recessive, ss) or BbSs and Bbss (if the male is heterozygous, Ss), and the expected phenotypes would be red eyes in both cases.