You start your experiments with the eyeless mutation on chromosome IV. You cross

Question

You start your experiments with the eyeless mutation on chromosome IV. You cross the reciprocal translocation strain to the eyeless pure line to generate F1 flies that are both translocation heterozygotes and Ee heterozygotes. You decide to testcross F1 males and females in two separate experiments to take advantage of the fact that crossing over does not occur in male Drosophila.

What can you conclude from these results? Select all statements that are true.

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My failed attempts:

You are attempting to map the breakpoints of a reciprocal balanced translocation in Drosophila. You have a line of flies that is homozygous for the translocation, and carries wild-type alleles for all loci. Drosophila are n4 (2n 8), with three autosomal pairs and the XX or XY pair. Based on your prior research, you know that the reciprocal translocation does not involve the X or Y chromosomes. You have strains with normal chromosomes that are homozygous for recessive markers on chromosomesand IV as follows: . The black mutation is on chromosome l, with bb black, and Bwild-type . The sepia mutation is on chromosome IlI, with ss sepia and Swild-type . The eyeless mutation is on chromosome IV, with eeeyeless and E wild-type To map the reciprocal balanced translocation, you perform several crosses and score the progeny as either fully fertile or semi-sterile in addition to the phenotypic marker in each cross Part A You start your experiments with the eyeless mutation on chromosome IV. You cross the reciprocal translocation strain to the eyeless pure line to generate F1 flies that are both translocation heterozygotes and Ee heterozygotes. You decide to testcross F1 males and females in two separate experiments to take advantage of the fact that crossing over does not occur in male Drosophila F1 males x pure eyeless females F1 females x pure eyeless males Cross (Note: There is no crossing over in the F1 males.) (Note: Crossing over may occur in the F1 females.) ¼ eyeless, fully fertile ¼ wild-type, semi-sterile ¼ eyeless, semi-sterile ¼ wild-type, fully fertile ¼ eyeless, fully fertile ¼ wild-type, semi-sterile ¼ eyeless, semi-sterile ¼ wild-type, fully fertile F2 Progeny What can you conclude from these results? Select all statements that are true O The F2 progeny in both experiments contain recombinants. The F2 progeny contain recombinants only when F1 females are testcrossed O None of the F2 progeny classes require crossing over Some of the F2 progeny classes require crossing over; others do not. O Chromosome IV is one of the chromosomes involved in the reciprocal balanced translocation.

Explanation / Answer

The correct statements are ............................

The F2 progeny in both experiments contain recombinants.

Chromosome IV is one of the chromosomes involved in reciprocal balanced translocation.

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