Question

How does DNA get copied into each of our cells and what happens if there is an error during this process

Answer 1

DNA gets copied to each new cell during cell division by "DNA Replication".

When there is an error during DNA replication, a "mutation" occurs.

Incorrectly paired nucleotides that still remain following the mismatch become permanent mutations after the next cell division. This is because once such mistakes are established, the cell no longer recognizes them as errors.