1.In Drosophila, yellow body color (y) is recessive and sex-linked. Brown eyes (bw), is found on chromosome 2. A third trait, Curly wings (Cy) is dominant and found on chromosome 3. Homozygosity for Cy is lethal in flies, whereas heterozygosity leads to expression of Curly wings. If we cross a yellow, brown female, with a male that expresses Curly, the resulting F1 will have two different female and male phenotypes. For the F1 x F1 cross you choose to cross F1 females expressing Curly with F1 males expressing yellow and Curly. In the F2 population, what is the probability of finding male flies expressing yellow, brown, but not Curly?

2.From the same F1 cross presented in the previous question, what is the probability of finding F2 male flies expressing Curly only?

3.In Drosophila, dumpy wings (dp) and black body (b) are recessive traits, both found on chromosome 2 separated by 35.5 map units. A wild type female is crossed to a homozygous recessive male for both traits. The F1 individuals are crossed to yield F2 flies. Among the F2, how many male flies would you expect to have dumpy wings but not black bodies if you scored a total of 850 flies?

Female F1 flies from the above question are also used in a test-cross to males expressing both traits. In the next generation, what proportion will be phenotypically wild-type?

Answer rating: 100% (QA)

Answer 1 Wild type body y Yellow body y Wild type eyes ... View the full answer