Question

Drosophila Melanogaster Mutations Cross

An apterous, brown, scarlet female is crossed with an apterous male. How would I figure out the phenotypes of the F2 generation? And the total expected number of offspring with each phenotype?

Answer 1

Perform the cross by punnet square first for F1 obtained by crossing apterous, brown , scaerlet female with apterous male and then self cross F1 to obtain F2.

To determine the phenotype first determine whether the mutation is X-linked or Autosomal resessive, then accordingly determine the phenotype by genotype. Most probably the mutation should be Autosomal recessive.

Then follow the mendelian ratio to determine the expected number of offspring with each phenotype.