This pre-assembled DNA model is built to a scale of 10 cm to 1 nm and accurately depicts a 16 base pair section of DNA. The phosphate-deoxyribose backbone and the four bases are represented by custom plastic moldings that show the shapes of the molecules in scale and illustrate the bonding between them. The handedness of the backbone chains and the relative sizes of the major and minor grooves in the relaxed molecule are correctly portrayed. The model is supported by a central pillar which can rotate on a circular stand. SMALL PARTS: NOT FOR CHILDREN UNDER 3 YRS. DNA Model 25" x 9" x 9".