What are the three types of mistakes that can occur in DNA synthesis?

During DNA synthesis, three primary types of mistakes can occur: base substitutions, where one nucleotide is incorrectly replaced with another; insertions, where extra nucleotides are added; and deletions, where nucleotides are missing. These errors can lead to mutations, potentially impacting gene function and organismal traits. Cellular proofreading mechanisms, such as DNA polymerases, help correct some of these mistakes, but not all errors are caught, which can result in lasting changes in the DNA sequence.