Put the steps of DNA replication in order:
- Helicase unzips the DNA molecule. 2. Primase creates a short RNA primer strand. 3. Starting at the primer, DNA polymerase elongates the new strand. 4. DNA polymerase proofreads the new strands. 5. DNA ligase joins together the Okazaki fragments. 6. DNA helicase rezips the DNA molecules.
The Correct Answer and Explanation is :
The correct order of the steps of DNA replication is as follows:
- Helicase unzips the DNA molecule.
- Primase creates a short RNA primer strand.
- Starting at the primer, DNA polymerase elongates the new strand.
- DNA polymerase proofreads the new strands.
- DNA ligase joins together the Okazaki fragments.
- DNA helicase rezips the DNA molecules.
Explanation of DNA Replication Steps
DNA replication is a critical process that occurs in all living organisms to ensure that genetic information is accurately copied and passed on during cell division. The process begins when helicase unwinds and separates the double-stranded DNA at specific regions called replication origins, creating a “replication fork.” This unzipping is essential as it provides single-stranded DNA templates for the new strands.
Next, primase synthesizes short RNA primers on the exposed single-stranded DNA. These primers provide a starting point for the DNA synthesis, as DNA polymerases can only add nucleotides to an existing strand. Once the primers are in place, DNA polymerase begins to synthesize the new DNA strands by adding complementary nucleotides to the primer. This elongation continues until the entire segment of DNA is replicated.
As DNA polymerase works, it also performs a proofreading function, checking each newly added nucleotide for errors. This step is crucial for maintaining the integrity of the genetic information, as any mistakes can lead to mutations.
In the case of the lagging strand, which is synthesized discontinuously, DNA ligase plays a vital role by joining together short segments called Okazaki fragments. These fragments are synthesized in short bursts due to the antiparallel nature of DNA strands.
Finally, after the entire DNA molecule has been replicated, DNA helicase helps to rewind the new strands, completing the replication process and ensuring that two identical DNA molecules are available for the daughter cells during cell division.