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2: How does DNA vary between individuals?

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    141877
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    Fundamentally, heritable variation between phenotype -- an individual's traits -- is due to heritable changes in genotype -- the genetic complement of of an individual's cells. This chapter describes the ways individuals' DNA may vary and the molecular methods used to determine an individual's genotype at these sites of variation (called molecular markers.) It also introduces several common uses for genetic markers; these uses are expanded in subsequent chapters.

    Learning Objectives

    At the end of this chapter, you should be able to:

    • Recall the definitions of each of the following types of polymorphism:
      • Restriction-fragment length polymorphism (RFLP)
      • Single-nucleotide polymorphism (SNP)
      • Tandem repeat polymorphism (SSR, microsatellite)
      • Copy-number variation
         
    • Describe the molecular mechanism behind the following laboratory methods:
      • Restriction digest
      • Agarose gel electrophoresis
      • Southern blot
      • PCR
      • Capillary electrophoresis
      • DNA microarray
         
    • Interpret the following kinds of experimental data:
      • Southern blots (to determine the alleles of an RFLP)
      • PCR & gel electrophoresis (to determine the alleles of a microsatellite)
      • DNA microarray (to determine SNP genotypes and copy number)
    • Describe, in general terms, how molecular markers are used


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