Question

Which type of DNA damage is repaired by the enzyme photolyase?

a) Single-strand breaks in the DNA backbone.
b) Apurinic sites.
c) Methylated or alkylated bases.
d) Thymine dimers.

Answer 1

Photolyase repairs thymine dimers in DNA.

Step-by-step explanation:

The enzyme photolyase repairs thymine dimers in DNA.

Thymine dimers are abnormal covalent bonds between adjacent thymine bases that are formed upon exposure to UV light.

Photolyase recognizes the thymine dimer and, in the presence of visible light, breaks apart the dimer, restoring the base pairing of the thymines with complementary adenines on the opposite DNA strand.