KENNETH EWARD / BIOGRAFX / SCIENCE PHOTO LIBRARY KENNETH EWARD / BIOGRAFX / SCIENCE PHOTO LIBRARY
DNA, computer artwork. DNA (deoxyribonucleic acid) consists of two strands (blue and yellow) of sugar phosphates forming a double helix (spiral). The strands are held together by interactions between nucleotide bases (yellow, horizontal) on each strand. There are four types of nucleotide base, but only two base pairings are usually possible: adenine to thymine, and cytosine to guanine. This means each DNA strand is a complementary copy of the other, allowing DNA replication. The base sequence along the molecule is the inherited genetic code that controls growth and development. DNA is stored in cell nuclei.
Model release not required. Property release not required.