Question

What happens after the DNA polymerase on the lagging-strand template completes an Okazaki fragment?

(a) DNA ligase removes the RNA primer and replaces it with DNA to form a continuous new DNA strand.
(b) The DNA polymerase dissociates from the replication complex and is replaced by a new polymerase.
(c) The Okazaki fragment dissociates from the lagging-strand template, attracting a DNA ligase.
(d) The sliding clamp attached to the polymerase dissociates from the DNA and the polymerase temporarily releases the lagging-strand template.
(e) The sliding clamp pushes the DNA polymerase to the next RNA primer on the lagging strand.

Answer 1

After the DNA polymerase on the lagging-strand template completes an Okazaki fragment, DNA ligase removes the RNA primer and replaces it with DNA to form a continuous new DNA strand.

Step-by-step explanation:

The correct answer is (a) DNA ligase removes the RNA primer and replaces it with DNA to form a continuous new DNA strand.

After the DNA polymerase on the lagging-strand template completes an Okazaki fragment, DNA ligase plays a key role in joining the newly synthesized DNA fragment with the previously synthesized DNA.

Once the RNA primer is removed by the exonuclease activity of DNA polymerase I, DNA ligase catalyzes the formation of phosphodiester linkages between the 3'-OH end of one nucleotide and the 5' phosphate end of the other fragment, resulting in a continuous new DNA strand.