NEETZoologyMolecular Basis of Inheritance
What is the difference between the S strain and the R strain of Streptococcus pneumoniae?
Options
- AThe S strain is virulent while the R strain is not
- BThe S strain produces smooth colonies while the R strain produces rough colonies
- CThe R strain is virulent while the S strain is not
- DThe R strain produces smooth colonies while the S strain produces rough colonies
Correct answer
B. The S strain produces smooth colonies while the R strain produces 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