HISC45H3 Lecture 1: Class 9 Notes Oct 4 BIOC15 (1)
Document Summary
Office hours between now and test 1 (october 18th) Tuesday october 17th 2-6 then back to normal for rest of course. Now let"s discuss of how recombination frequencies can be used to map genes that are in the same linkage group to their positions on chromosomes. Remember every bivalent (pair of synapsed homologous chromosomes) must have at least one crossover [to tie the chromosomes together to ensure they will orient to opposite poles at metaphasei], and most have at least two. Morgan and his students realized that the closer together two genes are along a chromosome the less likely it will be that a crossover will occur between them. Conversely, the farther apart two genes are, along a chromosome, the more likely they are going to be separated by a crossover. In fact, two genes that are on opposite ends" of a chromosome will always have a crossover between them because at least one crossover has to occur per chromosome.
