Chapter 11 provides knowledge of DNA and Its role in heredity. In this chapter, we will address the following questions: What is the evidence that the gene is DNA? What is the evidence that the gene is DNA? How is DNA replicated? How are errors in DNA repaired? What are some applications of our knowledge of DNA structure and replication? | DNA and Its Role in Heredity 11 DNA and Its Role in Heredity What Is the Evidence that the Gene Is DNA? What Is the Structure of DNA? How Is DNA Replicated? How Are Errors in DNA Repaired? What Are Some Applications of Our Knowledge of DNA Structure and Replication? What Is the Evidence that the Gene Is DNA? By the 1920s, it was known that chromosomes consisted of DNA and proteins. A new dye stained DNA and provided circumstantial evidence that DNA was the genetic material: It was in the right place It varied among species It was present in the right amount What Is the Evidence that the Gene Is DNA? Frederick Griffith, working with two strains of Streptococcus pneumoniae determined that a “transforming principle” from dead cells of one strain produced a heritable change in the other strain. Figure Genetic Transformation of Nonvirulent Pneumococci What Is the Evidence that the Gene Is DNA? Identifying the transforming principle, Oswald Avery: Treated samples to destroy different molecules; if DNA was destroyed, the transforming principle was lost. Figure Genetic Transformation by DNA (Part 1) Figure Genetic Transformation by DNA (Part 2) What Is the Evidence that the Gene Is DNA? Hershey-Chase experiment: Determined whether DNA or protein is the genetic material using bacteriophage T2 virus. Bacteriophage proteins were labeled with 35S; the DNA was labeled with 32P. Figure Bacteriophage T2: Reproduction Cycle Figure The Hershey–Chase Experiment (Part 1) Figure The Hershey–Chase Experiment (Part 2) What Is the Evidence that the Gene Is DNA? Next, genetic transformation of eukaryotic cells was demonstrated—called transfection. Use a genetic marker—a gene that confers an observable phenotype. Any cell can be transfected, even an egg cell—results in a transgenic organism. Figure Transfection in Eukaryotic Cells What Is the Structure of DNA? The structure of DNA was determined using | DNA and Its Role in Heredity 11 DNA and Its Role in Heredity What Is the Evidence that the Gene Is DNA? What Is the Structure of DNA? How Is DNA Replicated? How Are Errors in DNA Repaired? What Are Some Applications of Our Knowledge of DNA Structure and Replication? What Is the Evidence that the Gene Is DNA? By the 1920s, it was known that chromosomes consisted of DNA and proteins. A new dye stained DNA and provided circumstantial evidence that DNA was the genetic material: It was in the right place It varied among species It was present in the right amount What Is the Evidence that the Gene Is DNA? Frederick Griffith, working with two strains of Streptococcus pneumoniae determined that a “transforming principle” from dead cells of one strain produced a heritable change in the other strain. Figure Genetic Transformation of Nonvirulent Pneumococci What Is the Evidence that the Gene Is DNA? Identifying the transforming principle, Oswald .
