The Watson-Crick model shows how DNA can be replicated in an orderly fashion, a prime requirement for genetic material. Replication is accomplished semiconservatively; that is, one double helix is replicated into two identical helices, each with identical linear orders of nucleotides, and each of the two new double helices is composed of one old and one newly polymerized strand of DNA. This semiconservative replication occurs in both prokaryotes and eukaryiotes.