Question

Which eukaryotic DNA polymerase appears to play a role in nuclear DNA replication since replication cannot be completed in cells lacking this polymerase, even though its exact role has not yet been determined?

a. polymerase γ
b. polymerase δ
c. polymerase ε
d. polymerase β
e. polymerase α

Answer 1

DNA polymerase δ (delta) is essential for nuclear DNA replication in eukaryotic cells, and its absence prevents replication from being completed.

Step-by-step explanation:

The eukaryotic DNA polymerase that plays a pivotal role in nuclear DNA replication is polymerase δ (delta). In cells lacking this polymerase, replication cannot be completed, illustrating its essential function in the DNA replication process. The role of DNA polymerase δ is comparable to DNA polymerase III in prokaryotes, and it operates in association with proliferating cell nuclear antigen (PCNA) to effectively synthesize the leading and lagging strands of DNA during replication. On the other hand, DNA polymerase α (alpha) plays a role in initiating replication by synthesizing a short RNA primer to which it adds a few DNA nucleotides, making it important for starting the replication process.

DNA replication in eukaryotes involves several DNA polymerases. However, the eukaryotic DNA polymerase that appears to play a crucial role in nuclear DNA replication is polymerase α.

This is because replication cannot be completed in cells lacking polymerase α.

While the exact role of polymerase α in replication has not yet been determined, it is known to initiate synthesis of both leading and lagging strands.