1. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Chapter 11 Introduction To Genetics Section 11-5 Linkage & Gene Maps

2. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Gene Linkage Thomas Hunt Morgan 1910 Using Fruit Flies –Discovered Linkage Some Genes Are Inherited Together Counter To Mendel's Principle Of Independent AssortmentSome Genes Are Inherited Together Counter To Mendel's Principle Of Independent Assortment Turns Out, It Is The Chromosomes That Sort Independently, Not Individual Genes.Turns Out, It Is The Chromosomes That Sort Independently, Not Individual Genes.

3. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Gene Linkage Why Did Mendel Miss This?Why Did Mendel Miss This? –Six Of The Seven Genes He Studied Were On Different Chromosomes. –The Two That Were On The Same Chromosome Were So Far Apart That They Also Assorted Independently.

4. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Gene Maps Are Two Genes On The Same Chromosome Linked Forever? No! They Can Separate If Crossing Over Occurs In Meiosis Crossing Over Occurs In Meiosis This Produces New Combinations Of Alleles And Creates Genetic Diversity

5. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Gene Linkage Sturtevant, 1911Sturtevant, 1911 –Morgan’s Student –Realized The Farther Away Genes Were From Each Other, The More Likely They Would Be Separated If Crossover Occurred –This Allows Gene Mapping

6. FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT Gene Map - Linkage