Linkage and Crossing over. Lecture 5 Dr. Attya Bhatti. Linkage. Linkage is defined genetically as the failure of two genes to assort independently. Linkage occurs when two genes are close to each other on the same chromosome.
Researchers thought that physical coupling between the dominant alleles P and L and between the recessive alleles p and l might have prevented their independent assortment in the F1.
(43 + 22) ÷ 14513 = 1.4 percent.
The two genes T and U are farther apart on a chromosome than V and W. Chromatids cross over between T and U in a larger proportion of meioses than between V and W, so the recombinant frequency for T and U is higher than that for V and W.
The place on the map and on the chromosome where a gene is located is called the gene locus (plural, loci).