DNA polymerase I is an essential enzyme found in all living organisms. It plays a crucial role in DNA replication, the process by which cells copy their genetic material. This enzyme adds nucleotides to a growing DNA strand, ensuring that the new strand is complementary to the template strand. In addition to its role in replication, DNA polymerase I also has proofreading abilities. It can detect and correct errors in the DNA sequence, which helps maintain the integrity of the genetic information. This function is vital for preventing mutations that could lead to diseases or developmental issues.