複選題
27.Which of the following statements is/are TURE about DNA repair and proofreading?
(A) DNA repair mechanisms usually require an endonuclease to nick the duplex, so the repair enzymes can
access to the end of a DNA strand.
(B) Since DNA Polymerase II has endonuclease activity, it is able to proofread its product when it is used in
(C) The newly synthesized strand of DNA lacks methylated bases and other modifications allow repair
enzymes to distinguish in correct bases in DNA
(D) The proofreading of DNA is especially good because "the identity of each base pair is checked after the
enzyme moves on to the next base pair."
(E) Nucleotide excision has an intermediate where in a region of single stranded DNA is temporarily created.