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The Griffith Experiment definitions

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  • Griffith Experiment
    A 1928 study revealing that bacteria can acquire genetic traits from external sources, leading to changes in their characteristics.
  • Transformation
    The process where bacteria uptake external DNA, resulting in changes to both genotype and phenotype.
  • S Strain
    A lethal, smooth-surfaced pneumococcus variant with a capsule, capable of killing mice in experiments.
  • R Strain
    A nonlethal, rough-surfaced pneumococcus variant lacking a capsule, unable to kill mice.
  • Capsule
    A protective outer layer found on certain bacteria, contributing to their smooth appearance and virulence.
  • Heat-Killed S Strain
    A form of the lethal smooth bacteria rendered nonviable by exposure to high temperatures, unable to reproduce or cause disease.
  • Genetic Material
    The substance responsible for controlling traits in organisms, later identified as DNA.
  • Phenotypic Change
    An observable alteration in an organism's traits resulting from the acquisition of new genetic information.
  • Genotypic Change
    A modification in the genetic composition of an organism due to the uptake of external DNA.
  • Oswald Avery
    A scientist who, along with colleagues, identified DNA as the transforming substance in bacterial transformation.
  • DNA
    A molecule later proven to be the hereditary material responsible for transmitting genetic information in living organisms.
  • Protein
    A macromolecule once considered a candidate for genetic material due to its complexity and abundance in cells.
  • Virulence
    The degree to which a microorganism can cause disease, often influenced by structural features like capsules.
  • Uptake
    The absorption of external genetic material by a living cell, leading to transformation.
  • Skepticism
    The scientific doubt regarding DNA's role as genetic material, prevalent before its function was fully established.