This silent animation from The Secret of Life: Immortal Thread presents a detailed look at what happens during DNA replication. The animation demonstrates three processes: replication, in which DNA strands unwind and separate from one another and each strand's nucleotide sequence is copied; base pairing, in which nucleotide bases are matched with their counterparts (As with Ts, Cs with Gs) and bound together like the rungs of a ladder; and mutation, in which a base pair is mismatched and the faulty DNA sequence may be incorporated into a gene.