Final answer:
RNA carries the genetic information in tobacco mosaic virus, as demonstrated by Fraenkel-Conrat and Singer. The correct option is b.
Step-by-step explanation:
Fraenkel-Conrat and Singer demonstrated that RNA carries genetic information in tobacco mosaic virus. Other classic experiments by researchers like Hershey and Chase helped confirm that DNA was the primary source of heritable information in DNA viruses.
However, in the particular case of tobacco mosaic virus, it is the RNA that stores and transmits genetic information necessary for the virus reproduction. This finding was significant because, at the time, it was commonly believed that proteins, due to their complexity, were more likely to carry genetic information.
In tobacco mosaic virus, it is the RNA molecules that are responsible for encoding the genetic instructions passed from one generation to another.
Therefore, the correct option is b.