Comments on: 3.3 identify that DNA is a double-stranded molecule twisted into a helix with each strand, comprised of a sugar-phosphate backbone and attached bases, adenine (A), thymine (T), cytosine (C) and guanine (G), connected to a complementary strand by pairing the bases, A-T and G-C index.html Just another WordPress site hourly 1 http://wordpress.org/?v=3.5