Question

The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that will be joined together to form a finished lagging strand. The experiments that led to the discovery of Okazaki fragments gave evidence for which of the following ideas? The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that will be joined together to form a finished lagging strand. The experiments that led to the discovery of Okazaki fragments gave evidence for which of the following ideas? DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication. DNA is the genetic material. DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and cytosine. Bacterial replication is fundamentally different from eukaryotic replication.

Answer 1

The discovery of Okazaki fragments supported the idea that DNA polymerase is a directional enzyme that synthesizes DNA in a 5' to 3' direction for both leading and lagging strands. The lagging strand is made in short segments, each initiated by an RNA primer, while the leading strand is synthesized continuously.

Step-by-step explanation:

The experiments that led to the discovery of Okazaki fragments provided evidence that DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication. The lagging strand is synthesized in short segments, which means that the DNA polymerase must work in a discontinuous fashion on this strand, unlike the continuous synthesis on the leading strand. The discovery of the Okazaki fragments effectively showed that DNA replication involved short segments being joined together, supporting the idea that DNA polymerase works in a specific direction and requires a primer to initiate the synthesis of DNA.

The lagging strand is synthesized as a series of Okazaki fragments, each needing a RNA primer for initiation of synthesis. These RNA primers are eventually replaced by DNA nucleotides, and the fragments are joined by the action of DNA ligase. On the leading strand, DNA polymerase synthesizes DNA continuously in the direction of the replication fork, only requiring a single RNA primer to begin synthesis.

Answer 2

The correct answer is: DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication

DNA polymerase is an enzyme that synthesizes DNA during the DNA replication by adds nucleotides to the 3’ end of a primer. This means that the new chain is formed in a 5’ → 3’ direction.

Because double-stranded DNA is antiparallel, DNA polymerase moves in opposite directions on the two strands-leading and lagging strand. The leading strand is copied continuously since DNA polymerase is moving towards the replication fork. The lagging strand is copied discontinuous. DNA polymerase is moving away from the replication fork (and helicase that separates the strands), so it must constantly return to copy newly separated stretches of DNA. So, the lagging strand is copied as a series of short fragments-Okazaki fragments that are joined together by a combination of DNA pol I and DNA ligase.