Lecture 9-Mapping to Sex Linkage

Lecture 9-Mapping to Sex Linkage - Lecture 9- Mapping to...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 9- Mapping to Sex Linkage Two Linked Genes -If two genes, P and Q are i) linked in “trans” (repulsion) and ii) seperated by 20 map units, what would be the frequency of homozygous recessive offspring from a PpQq x PpQq cross? …. < 25% Map Distance -The % of recombinant progeny from a test cross -If you count the recombinant offspring, you can determine how far away the genes are on the chromosome -Recombination frequencies can be used to build genetic maps showing the relative location of genes on chromosomes -Genes a and c are located so far apart that a crossover almost always occurs between them. -Therefore, the % recombinant progeny will be 50%- just as it would be if the genes were on separate chromosomes -Therefore, these genes would appear to be unlinked -Genes a and b, and b and c, however, are close enough to show linkage; a and c must therefore also be linked Sex Chromosomes -Recall for humans…. -X is much larger than Y
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/04/2009 for the course BIOLOGY 1222 taught by Professor Haffie during the Spring '09 term at UWO.

Ask a homework question - tutors are online