Which statement is true regarding the recruitment of primases during replication?

Which statement is true regarding the recruitment of primases during replication?

• A. They are recruited prior to DNA helicases
• B. They initiate the formation of Okazaki fragments
• C. They are recruited after S-Cdk activation
• D. They are not critical for DNA synthesis

Answer: (C)

The statement regarding the recruitment of primases during replication is accurate in that primases are indeed recruited to initiate DNA synthesis, particularly after the activation of S-Cdk. S-Cdk, or S phase cyclin-dependent kinases, play a crucial role in the entry into the S phase of the cell cycle, which is when DNA replication takes place. For DNA replication to proceed, the primase synthesizes short RNA primers, which are necessary for DNA polymerases to begin adding DNA nucleotides. This process is essential because DNA polymerases cannot initiate synthesis de novo; they require a primer. Therefore, primases are integral to the formation of the primer that sets the stage for the entire replication process. In the context of other options, it should be noted that primases are typically recruited after helicases, which help to unwind the DNA helix, facilitating access to the single-stranded DNA that primases act upon. Additionally, while primases do initiate the formation of RNA primers for Okazaki fragments on the lagging strand, the question refers specifically to their recruitment timing rather than their function. Lastly, primases are indeed critical for DNA synthesis because without them, replication cannot initiate, highlighting their importance in successfully copying the genome.

The statement regarding the recruitment of primases during replication is accurate in that primases are indeed recruited to initiate DNA synthesis, particularly after the activation of S-Cdk. S-Cdk, or S phase cyclin-dependent kinases, play a crucial role in the entry into the S phase of the cell cycle, which is when DNA replication takes place.

For DNA replication to proceed, the primase synthesizes short RNA primers, which are necessary for DNA polymerases to begin adding DNA nucleotides. This process is essential because DNA polymerases cannot initiate synthesis de novo; they require a primer. Therefore, primases are integral to the formation of the primer that sets the stage for the entire replication process.

In the context of other options, it should be noted that primases are typically recruited after helicases, which help to unwind the DNA helix, facilitating access to the single-stranded DNA that primases act upon. Additionally, while primases do initiate the formation of RNA primers for Okazaki fragments on the lagging strand, the question refers specifically to their recruitment timing rather than their function. Lastly, primases are indeed critical for DNA synthesis because without them, replication cannot initiate, highlighting their importance in successfully copying the genome.