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Ch. 5 - Chromosome Mapping in Eukaryotes
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All textbooksKlug 12th EditionCh. 5 - Chromosome Mapping in EukaryotesProblem 9

Chapter 5, Problem 9

The genes dumpy (dp), clot (cl), and apterous (ap) are linked on chromosome II of Drosophila. In a series of two-point mapping crosses, the following genetic distances were determined. What is the sequence of the three genes? dp–ap 42 dp–cl 3 ap–cl 39

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Hello everyone here We have a question telling us that three genes S. T. And Q. Were linked on a chromosome. These genes have the following recombination frequencies. S. T. 35%. S. Q. 39%. T. Q. 4%. And the question is which of the following shows the correct sequence of these genes in the chromosome? So first we want to find which genes have the greatest recombination frequency. Those will be our outermost jeans. So in this case it is S. And Q. So we know that S. And Q. Our outermost genes which leaves T. Being in the middle. So our correct sequence is S. T. Q. Which is option A Thank you for watching. Bye!
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