Discussion:
Drosophilla crosses
1. In a lab strain of Drosophila, cinnabar (cn) and brown (bw) are recessive eye colour mutations known to be 41 m.u. apart on chromosome
2. When similar mutant alleles were induced in a strain from nature, the same linkage of cn and bw was observed. However, when a wild-type strain from nature was crossed with a cn bw/cn bw lab strain to create the genotype + +/cn bw, and females of this type were test-crossed to cn bw/cn bw males from the lab strain, the following phenotypic proportions were observed in the progeny:
+ + 25,200
cn bw 21,009
cn + 11
+ bw 36
3. What is unexpected about these results?
4. What is the most likely explanation? (Draw a diagram)
5. On the diagram show the precise origin of the cn + and the + bw classes.
Write your answer/response in detail with examples and facts and figures using APA style of formatting, size 12, font Times new roman and answer must be single spaced