Refer to the treatments listed below to answer the following question(s).
You isolate an infectious substance that is capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, or prion. You have four methods at your disposal that you can use to analyze the substance in order to determine the nature of the infectious agent.
I. Treat the substance with nucleases that destroy all nucleic acids and then determine whether it is still infectious.
II. Filter the substance to remove all elements smaller than what can be easily seen under a light microscope.
III. Culture the substance by itself on nutritive medium, away from any plant cells.
IV. Treat the sample with proteases that digest all proteins and then determine whether it is still infectious.
-If you already knew that the infectious agent was a prion, which treatment would allow you to distinguish this?

Question

Quizplus · Accepted Answer

Prions are infectious agents composed solely of protein. Treatment with proteases (IV) would destroy the prion and render it non-infectious, while treatment with nucleases (I) would have no effect.

Refer to the Treatments Listed Below to Answer the Following