The boss in your laboratory has just heard of a proposal by another laboratory that genes for eye color and the length of body bristles may be linked in Drosophila. Your lab has numerous pure-breeding stocks of Drosophila that could be used to verify of refute genetic linkage. In Drosophila, red eyes
a. Give the genotypes of the pure-breeding parental-files, and the genotype
b. In your experimental design, what are the genotype and phenotype of the line you propose to cross to the F1 to obtain the most useful information about genetic linkage between the eye color and bristle-length genes? Explain why you make this choice.
c. Assume the eye color and bristle-length genes are separated by
d. How would the results of the cross differ if the genes are not linked?
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Genetic Analysis: An Integrated Approach (3rd Edition)
- Sepia eyes, spineless bristles, and striped body are three recessive mutations in Drosophila found on chromosome 3. A genetics student crosses a fly homozygous for the alleles encoding sepia eyes, spineless bristles, and striped body with a fly homozygous for the wild-type alleles—encoding red eyes, normal bristles, and solid body. The female progeny are then test-crossed with males that have sepia eyes, spineless bristles, and striped body. Assume that the interference between these genes is 0.2 and that 400 progeny flies are produced by the testcross. Based on the map distances provided in Figure , predict the phenotypes and proportions of the progeny resulting from the test cross.arrow_forwardA homozygous strain of corn that produces yellow kernels is crossed with another homozygous strain that produces purple kernels. When the F1 are interbred, 197 of the F2 are yellow and 153 are prurple. Give the genotypes of the yellow and purple F2 and propose a genetic model that explains the inheritance of these kernel colors in corn.arrow_forwardIn mice, the trait for high cholesterol is specified by a dominant allele designatedHC, whereas the wild-type allele for normal cholesterol levels is designated hc.Black fur is specified by a recessive allele designated bl, whereas the wild-typeallele which gives brown fur is designated BL. The genes for both of these traitsare 30cM apart on the same autosome. A brown female (#1) with high cholesterolis mated to a black male (#2) with normal cholesterol. The progeny from this crossinclude a brown male (#3) with high cholesterol and a black female (#4) withnormal cholesterol. Mouse #3 is mated to a brown female (#5) with normalcholesterol. If 4 mice are produced from this cross, what is the probability that all 4will have brown fur?arrow_forward
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