Question

Which of the following could cause double strand breaks in the DNA? Group of answer choices

continuous exposure to long-wavelength radiation

continuous exposure to ethidium bromide, an intercalating agent

continuous exposure to X-ray radiation

continuous exposure to alkylating agents

Answer 1

Ans.) Option C : Continuous exposure to X-ray radiation

Explanation: Double strand breaks in DNA are caused by continous exposure to higher energy radiation (like UV) or X rays and certain chemicals. High energy radiation have smaller wavelength .

EtBr acts as intercalating agent and gets incorporated in double stranded structure and distors its helical structure but donot cause double stranded break.

Alkylating agents adds alkyl groups to the bases and modifies its structure.

Long wavelength radiations have lower energy and are not capable of causing ds DNA break.