In Drosophila, Three Autosomal Genes Have Alleles as Follows: Straight

question 186

Multiple Choice

In Drosophila, three autosomal genes have alleles as follows: Straight bristles (Hk) is dominant over hooked bristles (hk) ; straight wings (A) is dominant over arc wings (a) ; and red eye (Bw) is dominant over brown eye (bw) .Two test crosses were performed, with the results shown in the table. What linkage can you determine from these crosses?

• A) Only Hk and A are linked, with a distance of 45.3 units.
• B) Only A and Bw are linked, with a distance of 5.3 units.
• C) Only Hk and Bw are linked, with a distance of 40.0 units.
• D) None of the genes are linked.
• E) All of the genes are on the same chromosome; Hk and A are 45.3 units apart, and A and Bw are 5.3 units apart.