Allow kids to reflect on the basic structure of the DNA molecule (image below) and challenge them to suggest how this molecular structure provides both a code for genetic traits and a simple means for exact replication, the two basic requirements for a molecule that serves as a gene (unit of heredity). Hints: the bases (A, T, G, C) down one strand of the helix may occur in any order; the other strand will reflect the same order but with opposite bases; the base pairs are held together with weak hydrogen bonds.
Yes, the order of bases down one side of the helix is code for the putting amino acids together in the proper order for making given proteins. The weak hydrogen bonds between base pairs allow the molecule of come apart like a zipper. Each side then acts a template for making a new half via complement base pairing. The result is two like molecules, (half old, half new) in place of the one. (The actual processes of these operations is complex. Pursue finding further videos as you wish.)