Question

during dna replication, which of the following enzymes covalently connects segments of dna?
helicase
dna polymerase iii
ligase
dna polymerase i

Explanation:

To solve this, we analyze each enzyme's role in DNA replication:

• Helicase: Unwinds the DNA double helix, not for connecting segments.
• DNA polymerase III: Synthesizes new DNA strands (adds nucleotides), not for connecting segments.
• Ligase: Forms covalent bonds (phosphodiester bonds) to join Okazaki fragments (DNA segments) on the lagging strand.
• DNA polymerase I: Removes RNA primers and replaces them with DNA, not for connecting segments.

Answer:

C. ligase