Final answer:
The three forms of the DNA double helix are A-DNA, B-DNA, and Z-DNA, with B-DNA being the most common form in cells. Differences in the helical twist and stabilization methods, like hydrogen bonds, give each form its unique characteristics.
Step-by-step explanation:
Forms of the DNA Double Helix
The double helical structure of DNA, famously identified by Watson and Crick, assumes three major forms known as A-DNA, B-DNA, and Z-DNA. Each form is a variation of the double helix and has unique characteristics because of differences in their helical twist and the way they are stabilized by hydrogen bonds. the binding of complementary bases is crucial for the stability of the DNA double helix, no matter which form it takes. The hydrogen bonds between bases at the center of the helix play an essential role in maintaining the structure.