Which of the Following DNA Alterations Can Be Corrected by Light-Dependent

Question

Which of the following DNA alterations can be corrected by light-dependent repair?
A) Methylation
B) Thymine dimers
C) Mismatched basepairing
D) Hydroxylation
E) Inversions

Accepted Answer

Thymine dimers are formed when adjacent thyminebases in a DNA strand form covalent bonds with each other, leading to a deformation in the DNA that interferes with replication and transcription. Light-dependent repair, also known as photoreactivation, uses the energy of visible light to break the covalent bond and restore the structure of the DNA. Methylation, mismatched basepairing, hydroxylation, and inversions are not corrected by light-dependent repair.