Question Detail

MIC 121 Mcb compilations Objective Question

Question

What is the primary mechanism by which UV-C light kills microorganisms?
Options
A Disruption of cell membranes
B Inhibition of metabolic enzymes
C Heating and denaturation of proteins
D Damage to DNA and RNA
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

The primary mechanism by which UV-C light (ultraviolet light in the C wavelength range) kills microorganisms is by causing damage to their nucleic acids (DNA and RNA). UV-C light induces the formation of pyrimidine dimers (e.g., thymine dimers), which interfere with DNA replication and transcription, leading to genetic mutations and cell death.

Hint

Think about the effect of high-energy radiation on genetic material.

Question Info