A Mutant Gene That Produces Brown Eyes (Bw)is Located on Chromosome

Short Answer

A mutant gene that produces brown eyes (bw)is located on chromosome #2 of Drosophila melanogaster,whereas a mutant gene producing bright red eyes,scarlet (st),is located on chromosome #3.Phenotypically,wild-type flies (with dull red eyes),whose mothers had brown eyes and whose fathers had scarlet eyes,were mated.The 800 offspring possessed the following phenotypes: wild type (dull red),white,scarlet (bright red),and brown.Most of the 800 offspring had wild-type eyes,whereas those with white eyes were the least frequent.
a) Using standard symbolism,diagram the cross from the P generatio $\text { (brown-eyed mothers } \times \text { scarlet-eyed fathers) }$ n and the F₁ generation.Be certain to provide the alleles of the mutant genes.
b) From the information presented above,how many white-eyed flies would you expect in the F₂ generation?