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NEETZoologyMolecular Basis of Inheritance

What was the difference between the S strain and R strain bacteria in Griffith's experiments?

Options

  1. AS strain bacteria were virulent while R strain bacteria were non-virulent.
  2. BS strain bacteria were heat-resistant while R strain bacteria were heat-sensitive.
  3. CS strain bacteria produced smooth colonies while R strain bacteria produced rough colonies.
  4. DS strain bacteria were antibiotic-resistant while R strain bacteria were antibiotic-sensitive.

Correct answer

C. S strain bacteria produced smooth colonies while R strain bacteria produced rough colonies.

Step-by-step solution

In 1928, Frederick Griffith, in a series of experiments with Streptococcus pneumoniae (bacterium responsible for pneumonia), witnessed a miraculous transformation in the bacteria. During the course of his experiment, a living organism (bacteria) had changed in physical form. When Streptococcus pneumoniae (pneumococcus) bacteria are grown on a culture plate, some produce smooth shiny colonies (S) while others produce rough colonies (R). This is because the S strain bacteria have a mucous (polysaccharide) coat, while

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