Item Type: DNA Model Material: PVC Use: 1. The base is connected to deoxyribose with a thick rod. 2. Phosphoric acid is connected to deoxyribose by a thin rod. 3. The bases should be paired, A to T, C to G. 4. The ratio of bases in the molecular structure of DNA is (A+G) /(T+C)=1. 5. Polynucleotide double chains, rotating 360 around a major axle, can form a trapezoidal DNA double helix. Each helix contains 10 base pairs. 1Ideal model for teaching, for students, for the education of biological class and lboratory research. 2Vivid and detailed image, restore the details of DNA model, give the students deepest effect on the biology class. 3Training color recognition ability, hand capacity and imagination, motivate potential. 4Smooth surface of the model without burrs, without damage to children's hands, effectively develop children's intelligence. 5It is a demonstration model of biology teaching in school and can also be used as reference for biology major in colleges and universities.Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.10 x Connector Rod20 x White Ball20 x Blue Ball40 x White Connector Rod