Chapter 11 Introduction To Genetics

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Chapter 11Introduction To Genetics

• Section 11-5
• Linkage Gene Maps

2
Gene Linkage

• Thomas Hunt Morgan
• 1910 Using Fruit Flies
• Discovered Linkage
• Some Genes Are Inherited Together Counter To
  Mendel's Principle Of Independent Assortment
• Turns Out, It Is The Chromosomes That Sort
  Independently, Not Individual Genes.

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Gene Linkage

• 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
Gene Maps

• Are Two Genes On The Same Chromosome Linked
  Forever?
• No!
• They Can Separate If
• Crossing Over Occurs In Meiosis
• This Produces New Combinations Of Alleles And
  Creates Genetic Diversity

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Gene Linkage

• Sturtevant, 1911
• Morgans Student
• Realized The Farther Away Genes Were From Each
  Other, The More Likely They Would Be Separated If
  Crossover Occurred
• This Allows Gene Mapping

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Gene Map - Linkage