What constitutes the outer backbone of the DNA helix?

The outer backbone of the DNA helix is made up of sugars and phosphates. In the structure of DNA, the sugar component is deoxyribose, and it alternates with phosphate groups to form the backbone, which runs along the length of the double helix. This sugar-phosphate backbone provides structural support and stability to the DNA molecule, allowing it to maintain its shape.

Each sugar molecule is connected to a nitrogenous base, which contains the genetic information. The specific sequence of these bases encodes genetic instructions, while the sugars and phosphates form the repeating units that connect those bases together. This configuration is essential for the integrity of DNA and plays a crucial role in its replication and function.

Overall, the correct composition of the DNA backbone as sugars and phosphates highlights the fundamental structure necessary for the molecule's functions in cellular processes.