Towering nearly 3 feet tall, this highly visible DNA molecule is ideally suited to lecture hall presentations. But your students will find it is even more effective for hands-on investigations into the functional unit of heredity. Magnetic connectors, representing hydrogen bonds, permit the two strands of the double helix to unzip completely, dramatically evoking the mechanism of DNA replication, and RNA synthesis (genetic transcription). A removable nucleotide lets your students experience first hand why a larger purine base must always pair with a smaller pyrimidine base, and that base pairs are complementary - adenine must pair with thymine, forming two hydrogen bonds, while guanine must mate with cytosine, forming three hydrogen bonds. Non-separable atoms form the sugar-phosphate backbone of the molecule. Molded of high density polystyrene, and encompassing six base pairs, the double helix is supported on a hardwood stand which can be rotated for viewing from all angles. Complete with instructional guide, the model measures 34"Hx16"Diameter (86x41cm).