1) In Drosophila, black(b) body color and vestigial(v) wings are linked and are recessive to the normal traits, gray(+) body color and long (+) wings. Homozygous parents were crossed to give F₁ progeny. F₁ flies were then testcrossed with black, vestigial flies and 4 classes of testcross progeny were produced as follows:

gray, long 139 black, long 628

gray, vestigial 602 black, vestigial 131

Using the above data, do the following:

a) Diagram the chromosomes of the P₁, F₁, and testcross individuals and the crosses performed.

b) Diagram the formation of the crossover gametes.

c) Give the total progeny, the crossover progeny, and the percentage of crossing over.

d) Construct a chromosome map of these two loci.

2) In Drosophila, ebony(e) body color, pink(p) eye color and curled(c) wings are recessive to the normal traits, gray(+) body color, red(+) eye color and straight(+) wings. Homozygous parents were crossed to give F₁ progeny. F₁ flies were then testcrossed with ebony, pink, curled flies and 8 classes of testcross progeny were produced as follows:

gray, red, curled (e⁺p⁺c) 371 ebony, red, curled (ep⁺c) 101

ebony, pink, straight (epc⁺) 384 gray, pink, straight (e⁺pc⁺) 94

ebony, red, straight (ep⁺c⁺) 26 gray, red, straight (e⁺p⁺c⁺) 2

gray, pink, curled (e⁺pc) 19 ebony, pink, curled (epc) 3

Using the above data, perform the tasks assigned in a) through d) of problem 1. Remember to first obtain the order of the genes (show your work!)before you try to diagram the chromosomes and crosses. In addition, calculate the coefficient of coincidence and the interference for the double crossovers.

Answer rating: 100% (QA)

4 Black Body 16 recessine to gray body Long wings do... View the full answer