Biology Multiple Choice Questions on “The Genetic Material is DNA”.
1. What are the viruses that affect bacteria known as?
a) Virophage
b) Bacteriophage
c) Mimivirus
d) Virology
Answer: b
Clarification: The viruses that affect bacteria are known as bacteriophage. They have the capability to both enter the bacterium and reproduce inside them. Alfred Hershey and Martha Chase worked with these kinds of viruses.
2. Who proved that DNA was indeed the genetic material through experiments?
a) Alfred Hershey and Maclyn McCarty
b) Oswald Avery and Maclyn McCarty
c) Oswald Avery and Martha Chase
d) Alfred Hershey and Martha Chase
Answer: d
Clarification: Alfred Hershey and Martha Chase in the year of 1952 proved that DNA was the genetic material through experiments. They worked with bacteriophages. Oswald Avery and Maclyn McCarty helping in the determination of the biochemical natures from Griffith’s experiment with regards to the “transforming principle”.
3. The bacteria treats the attached viral particle’s (bacteriophage) genetic material as its own.
a) True
b) False
Answer: a
Clarification: The bacteriophage comes and attaches itself onto the top of the bacterial cell wall. After attachment, the virus makes contact with the bacterial cell wall and tries to inject its genetic material (DNA or RNA) into the bacteria. The bacteria will consider the viral genetic material to be as its own and will not do anything.
4. On which medium were the viruses cultivated by Alfred Hershey and Martha Chase?
a) A medium containing radioactive potassium (K)
b) A medium containing radioactive Uranium (U)
c) A medium containing radioactive phosphorous (P)
d) A medium containing potassium (K)
Answer: c
Clarification: Alfred Hershey and Martha Chase wanted to figure out whether it was the protein from the bacteriophage that was entering into the bacteria or if it was the DNA. So, they cultured the bacteriophage in a medium containing radioactive phosphorous. In this medium they observed that the radioactive DNA was present in the virus but not the radioactive protein. This is because, protein doesn’t contain phosphorous but on the contrary, the DNA does.
5. When the viruses are cultivated in the medium containing radioactive Sulphur, then these viruses possess radioactive DNA but not radioactive protein.
a) True
b) False
Answer: b
Clarification: DNA doesn’t contain Sulphur whereas protein does. So, when the virus is placed in the culture medium containing radioactive Sulphur, radioactive protein is produced and not the radioactive DNA. This is due to the presence of Sulphur in proteins.
6. The virus infected bacterium which contains radioactive proteins are not radioactive.
a) True
b) False
Answer: a
Clarification: The virus infected bacterium which contains the radioactive DNA, were observed to be radioactive in lab experiments. But this was not the case for the ones that had the radioactive protein in them. From this, it could be inferred that the protein molecules did not enter the bacterium but only DNA molecules did. The genetic material that is passed on from the virus to bacterium is the DNA.
7. Which of the following is not a stage in the “Hershey-Chase experiment”?
a) Blending
b) Centrifugation
c) Infection
d) Conjugation