What are DNA polymerases responsible for?

DNA polymerases are essential enzymes responsible for creating DNA molecules by assembling nucleotides in a specific sequence during the process of DNA replication. They play a critical role in copying the genetic material, ensuring that each new cell has an accurate copy of the DNA as it divides. The enzyme starts at the DNA template strand and adds complementary nucleotides, which are the building blocks of DNA, thus synthesizing a new DNA strand. This process is vital for cellular replication and for maintaining the integrity of the genetic information across generations.

The other options relate to different biological functions. Degrading RNA involves enzymes like RNases, which are not related to the function of DNA polymerases. Facilitating protein synthesis is the role of ribosomes and transfer RNA (tRNA), not DNA polymerases, which are directly involved in nucleic acid synthesis rather than protein synthesis. Additionally, regulating gene expression pertains to other factors such as transcription factors and regulatory RNA, rather than the direct synthesis activity of DNA polymerases.