Question

In his work with pneumonia-causing bacteria and mice, Griffith found that

1. the protein coat from pathogenic cells was able to transform non-pathogenic cells.
2. heat-killed pathogenic cells caused pneumonia.
3. some substances from pathogenic cells were transferred to non-pathogenic cells, making them pathogenic.
4. the polysaccharide coat of bacteria caused pneumonia.

Short answer

1. The option“the protein coat from pathogenic cells was able to transform non-pathogenic cells” is false.
2. The option “heat-killed pathogenic cells caused pneumonia” is false.
3. The option“some substances from pathogenic cells was transferred to non-pathogenic cells, making them pathogenic” is true.
4. The option “the polysaccharide coat of bacteria caused pneumonia” is false.

Step-by-step solution

 Step 1: Genetic material

Genetic materials are substance that is transferred from the parents to the offspring. There is some information encoded in the genetic material which determines the characters of the offspring. Some newly inherited characters are also seen in the offspring.

Explanation of option (A)

Protein coats are substances found in pathogenic cells. An example of the pathogenic cells that possess the protein coat is the virus. The capsid is the protein coat present in the viruses.

A protein coat is not the substance that was found in the Griffith experiment.

Therefore, the given statement is false.

Explanation of option (B)

The pathogenic cells are killed by applying heat, known as heat-killed pathogens. The heat pathogen gets disintegrated and tends to lose its pathogenicity.

Pneumonia is a disease is caused by live pathogenic cells, not the heat-killed pathogenic cells.

Therefore, the given statement is false.

Explanation of option (C)

Griffith experimented by injecting the pneumonia bacteria into the mice. He observed the conversion of non-pathogenic cells to pathogenic cells in the mice, which transfer virulence from the bacteria to the normal cells.

The observation made in the Griffith experiment is the transfer of substances that happens from the pathogenic cells to the non-pathogenic cells.

Therefore, the given statement is true.

Explanation of option (D)

Griffith did not conclude the substance polysaccharide is getting transferred from the pathogenic cells to the non-pathogenic cells.

Griffith does not conclude that substance transferred is a bacterial polysaccharide.

Therefore, the given statement is false.