What is the shape of the DNA molecule?

The DNA molecule is shaped like a double helix, which means it resembles a twisted ladder. This structure consists of two long strands of nucleotides coiled around each other. Each strand is made up of a backbone of sugar and phosphate groups, with the rungs of the ladder formed by pairs of nitrogenous bases. Adenine pairs with thymine, while cytosine pairs with guanine, creating base pairs that are held together by hydrogen bonds.

The double helix structure is essential for the function of DNA in storing and transmitting genetic information. It allows for the precise replication of DNA during cell division, as each strand can serve as a template for creating a complementary strand. This design also helps protect the genetic information, as the bases are located on the inside of the helix, shielding them from potential damage.

In contrast, other shapes mentioned, such as a triple helix, linear form, or single strand, do not accurately represent the known structure of DNA in biological organisms. While there are some instances of triple helices and single-stranded forms in specific contexts (like RNA or synthetic constructs), these do not apply to the standard structure of DNA found in most living organisms.