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The Griffith Experiment exam Flashcards

The Griffith Experiment exam
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  • Frederick Griffith
    A scientist who conducted a pivotal experiment in 1928 demonstrating bacterial transformation.
  • Transformation
    The process by which bacteria uptake external DNA, leading to changes in genotype and phenotype.
  • What did Griffith's experiment demonstrate?
    It demonstrated that bacteria can undergo transformation by uptaking external DNA.
  • R strain
    Non-lethal rough bacteria used in Griffith's experiment.
  • S strain
    Lethal smooth bacteria with a capsule, used in Griffith's experiment.
  • What happened when Griffith injected mice with the S strain?
    The mice died because the S strain is lethal.
  • Heat-killed S strain
    S strain bacteria that have been killed by heat and are non-lethal.
  • What was the result when Griffith injected mice with the R strain?
    The mice remained alive because the R strain is non-lethal.
  • What was the result when Griffith injected mice with the heat-killed S strain?
    The mice remained alive because the heat-killed S strain is non-lethal.
  • What surprising result did Griffith find in his fourth experiment?
    The combination of R strain and heat-killed S strain killed the mice.
  • What did Griffith conclude from his fourth experiment?
    The R strain transformed by uptaking genetic material from the heat-killed S strain.
  • Genotype
    The genetic makeup of an organism.
  • Phenotype
    The observable traits of an organism.
  • What did Griffith extract from the dead mice in his fourth experiment?
    Living S strain bacteria.
  • What was unknown during Griffith's time about the genetic material?
    The exact nature of the genetic material was unknown; it was later identified as DNA.
  • Oswald Avery, Maclyn McCarty, and Colin MacLeod
    Scientists who identified DNA as the transforming substance in Griffith's experiment.
  • What was the initial skepticism about DNA?
    Many scientists believed proteins were the genetic material because more was known about proteins than DNA.
  • What is the significance of Griffith's experiment?
    It laid the groundwork for identifying DNA as the genetic material.
  • What does the term 'capsule' refer to in the context of S strain bacteria?
    A smooth surface layer that makes the S strain lethal.
  • What did further experiments after Griffith's work aim to prove?
    That DNA, not proteins, is the genetic material.
  • What is the importance of the R strain's rough surface?
    It makes the R strain non-lethal.
  • What did Griffith's experiment help to identify?
    That some unknown genetic factor controls the traits of organisms.
  • What was the outcome when Griffith combined the R strain and heat-killed S strain?
    The combination killed the mice, indicating transformation.
  • What did Griffith's findings contribute to?
    The foundational understanding of genetic inheritance and transformation in microorganisms.
  • What did Griffith's experiment show about bacterial DNA?
    Bacteria can uptake external DNA from their environment.
  • What was the key finding from Griffith's fourth experiment?
    Living R strain bacteria transformed into lethal S strain bacteria.
  • What was the role of heat in Griffith's experiment?
    Heat was used to kill the S strain bacteria, making them non-lethal.
  • What did Griffith's experiment suggest about genetic material?
    That genetic material could be transferred between bacteria.
  • What was the broader impact of Griffith's experiment on science?
    It paved the way for the discovery of DNA as the genetic material.