Question

If the DNA of a virus is labelied with ³²P and the protein of the virus is labelled with ³⁵S, after transduction which molecules (s) would be present inside the bacterial cells.

Options

• Only ³²P

• Only ³⁵S

• Both (a) and (b) 

• None of these

Answer 1

Only ³²P

Explanation:

Bacteria infected with viruses containing radioactive DNA (incorporating = ³²P) were radioactive, showing that DNA was the substance transmitted from the virus to the bacteria. Bacteria inoculated with viruses containing radioactive proteins (incorporating ³⁵S) were not radioactive. As a result, DNA is the genetic material that is transmitted from virus to bacteria.