Chapter 19, Problem 7STP

Summary Introduction

Introduction :

Prions are proteinaceous infectious particles that can cause infection or disease. These coil-shaped protein particles exist in the cell. However, the function associated with these particles is not well understood.

Answer to Problem 7STP

Correct answer :

Option (B) by causing normal proteins to mutate.

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) by causing normal proteins to mutate. When the genes responsible for encoding these protein particles mutate, it results in the misfolding of the prion. This misfolding caused due to the mutation in the gene coding for prions cause diseases. The misfolded proteins of the prions can induce mutation in normal proteins that result in the misfolding of the other normal protein particles. 

Explanation for incorrect answer :

Option (A) by activation synthesis of viral RNA. Prions are proteinaceous particles. They do not have any genetic material. They do not interact with nucleic acids. Hence, it is an incorrect option.

Option (C) by deactivating part of the host’s DNA. Prions are proteinaceous and normally present in a cell. The mutated prions cause misfolding of normal proteins. They do not deactivate the host’s DNA. Hence, it is an incorrect option.

Option (D) by disrupting the way cells reproduce. Prions do not disrupt the process of cell division. However, they may cause the misfolding of the proteins associated with the process of cell division. Hence, it is an incorrect answer.