11-5. Gene Linkage and Mapping• Gene linkage – Thomas Hunt Morgan – Genes on the same chromosome are linked and usually inherited into the same gametes – It is the chromosome that assort independently, not individual genes
• Linkage and crossing over – linked genes may also seperate into different gametes – Because of crossing over – The farther apart two genes are on the same chromosome, the greater the chance of crossing over between them. Why?
A B C DCrossing over will disrupt linkage between Aand B more often than C and D
• Gene map – The relative locations of each known gene on one chromosomeExact location on chromosomes Chromosome 2
• Sex-linked • Genes on the sex chromosome (usually on x, called x-linked) • Eg: Color blindness gene, Hemophilia gene• Pedigree: a chart that shows genetic relationship in families male female mating offspring in order sex not known Have disorder