Question

Which element is found in the protein coat of T2 bacteriophage but absent from DNA?

Options

• Nitrogen

• Sulphur

• Phosphorus

• Oxygen

Answer 1

Sulphur (S) is present in amino acids cysteine and methionine, which are components of the protein coat. Sulphur is absent from DNA, making it an ideal marker for labeling proteins. This allowed researchers to distinguish between protein and DNA using radioactive isotopes.