Thymine Dimers are Dealt with By

Question

Thymine dimers are dealt with by
A)no repair mechanisms.
B)photoreactivation repair.
C)SOS repair.
D)excision repair.
E)photoreactivation repair AND excision repair.

Accepted Answer

Thymine dimers can be repaired by both photoreactivation repair and excision repair mechanisms. Photoreactivation repair is a process where the enzyme photolyase uses energy from visible light to break the bond between the two thymine bases in the dimer, allowing for the DNA strands to separate and the damaged bases to be repaired. Excision repair involves the removal of the damaged DNA strand by nucleases and the insertion of a new strand by DNA polymerase. Both mechanisms are used to repair thymine dimers in different organisms and under different conditions.