Question

Which of the statements describes what happens during mismatch repair of DNA? Enzymes identify the recently copied DNA strand, snip out a portion of the DNA strand that contains the mismatched nucleotides, and resynthesize the segment correctly. Enzymes copy the correct DNA sequence from the DNA in another cell, import the DNA sequence, and use the imported DNA sequence to repair the mismatched nucleotides. Enzymes cut out both strands of DNA containing the mismatched sequence, copy the same sequence from the homologous chromosome, and insert the copied sequence. Enzymes identify the newly copied DNA strand, delete the mismatched nucleotide, pull the gap closed, and join the nucleotides on either side of the gap togeth

Answer 1

Mismatch repair of DNA

Explanation:

Enzymes identify the recently copied DNA strand, snip out a portion of the DNA strand that contains the mismatched nucleotides, and resynthesize the segment correctly.

During DNA replication  spontaneous changes may occur . However, these changes are temporary because these are immediately repaired by a set of processes called DNA repair mechanisms. There are four categories of DNA repair system- Direct repair, Excision repair, Mismatch repair and recombination repair.

The mismatch repair system can detect mismatches that occur in DNA replication. The steps involved are:

• Recognize mismatched base pair,.
• Determine which base in the mismatch is the incorrect one.
• Excise the incorrect base and carry out repair synthesis.