What is the most impoant lesion produced in chromosomal DNA by exposure to ionizing radiation?
Correct Answer: Breaks on both DNA strands which are opposite each other or separated by only a few bases ('double-strand break')
Description: In intact DNA, single strand breaks (SSBs) are of little biologic consequence because they are repaired readily using the opposite strand as a template. If the repair is incorrect (misrepair), it may result in a mutation. If both strands of the DNA are broken and the breaks are well separated, repair again occurs readily, because the two breaks are handled separately.By contrast, if the breaks in the two strands are opposite one another or separated by only a few base pairs, this may lead to a double-strand break (DSB); that is, the piece of chromatin snaps into two pieces. Double-strand breaks are the most impoant lesions produced in chromosomes by radiation.Reference: Eric J Hall Textbook of Radiobiology for Radiologist; 5th edition
Category:
Radiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now