Question

Which of the following types of DNA damage cannot be repaired by base excision repair?
a. Depurination
b. Cytosine deamination
c. Thymine dimer
d. Single-strand break
e. Base oxidation

Answer 1

Answer:

c. Thymine dimer

Explanation:

Thymine dimer

Thymine dimer ( also called the DNA damage ) that is repaired by the nucleotide excision repair which involves the breakage of the phosphodiester bond on the side of the damage , and results in the excision of an oligolnueotide of 10-12 nucleotides in length .

But the base excision repair involves the removal of the damaged base , removal of short polynuceotide and resynthesis of this area with DNA polymerase .