In Griffith's experiment, which of the following bacterial strains was capable of causing pneumonia in mice?
1. | Live R |
2. | Bacteria strain with polysaccharide coat |
3. | Heat Killed S |
4. | Live R with capsule and Heat Killed S |
Assertion (A): | S-strain of Streptococcus pneumoniae is virulent. |
Reason (R): | Heat-killed S-strain Streptococcus pneumoniae injected into mice did not cause pneumonia and did not kill them. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | (A) is True but (R) is False. |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
4. | Both (A) and (R) are False. |
Frederick Griffith discovered:
1. | DNA is the genetic material |
2. | RNA can be the genetic material |
3. | Streptococcus has two strains |
4. | Bacterial transformation |
Prior to the work of Avery, Macleod, and McCarty, the genetic material was thought to be:
1. | DNA | 2. | RNA |
3. | Protein | 4. | Nucleotide |
In Avery, Macleod, and McCarty's experiment, the transformation of bacteria was inhibited by:
1. | Proteases | 2. | RNase |
3. | DNAs | 4. | None of these |
Assertion (A): | In Avery, Macleod, and McCarty's experiment, digestion of heat-killed lysate with proteases and RNases did not affect transformation but digestion with DNase did. |
Reason (R): | DNase will hydrolyse all biomolecules in the lysate except DNA. |
1. | (A) is True but (R) is False. |
2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
4. | Both (A) and (R) are False. |
Assertion (A): | Even after the results of Avery, Macleod, and McCarty's experiment, not all biologists were convinced that DNA is hereditary material. |
Reason (R): | Proteins were conclusively proved to be the genetic material for almost all living organisms. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are False. |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
4. | (A) is True but (R) is False. |
The unequivocal proof that DNA is the genetic material was provided by:
1. | Avery, Macleod, and McCarty |
2. | Hershey and Chase |
3. | Meselson and Stahl |
4. | Watson and Crick |
Viruses grown on radioactive sulfur contain:
1. | Radioactive proteins but not DNA |
2. | Radioactive DNA but not proteins |
3. | Radioactive proteins and DNA |
4. | Nonradioactive DNA and protein |
Hershey and Chase proved DNA as the genetic material in their experiment because :
1. | Bacteria that were infected with viruses that had radioactive proteins were not radioactive. |
2. | Bacteria that were infected with viruses that had radioactive DNA were radioactive. |
3. | Both 1 and 2 are correct. |
4. | Both 1 and 2 are incorrect. |