What does the outcome of the bacteriophage experiment suggest about the entry of molecules into host cells?

• A. Only DNA, not protein, can enter the host cell
• B. Bacteriophages consist only of DNA and protein
• C. Both DNA and protein can enter the host cell
• D. Only protein, not DNA, can enter the host cell

Answer: (B)

The correct answer illustrates that bacteriophages are composed of both DNA and protein, confirming that both components exist within these viruses. This foundational knowledge is essential in understanding the molecular structure of bacteriophages and their function during infection.

The experiment highlights the specific role of DNA in the entry process, as studies typically show that when bacteriophages infect bacterial cells, it is often the DNA that is injected into the host. The protein coat, or capsid, generally remains outside the cell. Therefore, the focus on the molecular composition of bacteriophages supports the idea that DNA is the genetic material responsible for directing the host cell's machinery to create new viral particles.

This reinforces the key principle that not all components of a virus enter the host cell during infection; rather, it is primarily the viral DNA that is injected. Understanding the composition of bacteriophages aids in deciphering how they hijack host cellular processes, and this knowledge forms a critical basis for further studies in molecular biology and virology.