Question

Assertion: In Griffith’s experiment mice were injected by a mixture of heat killed Smoothtype bacteria and live Rough type bacteria. Some mice died of pneumonia and theirblood contained both live Rough type bacteria and live Smooth type bacteria.

Reason: The dead Smooth type bacteria became alive and caused pneumonia.Griffith named it as transforming principle. *​

Answer 1

Answer:

Both assertion and reason are false.

Explanation:

When bacteria Streptococcus pneumoniae 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 R strain does not. Mice infected with the S strain (virulent) die from pneumonia infection but mice infected with the R strain do not develop pneumonia. In Griffith's experiment, some 'transforming principle', transferred from the heat-killed S strain, had enabled the R strain to synthesize a smooth polysaccharide coat and become virulent which must be due to the transfer of the genetic material. This is known as transformation.