The sugar used in DNA to make up the backbone is deoxyribose.

Here's why:

* Deoxyribose is a five-carbon sugar that forms the backbone of DNA. It's called deoxyribose because it lacks one oxygen atom compared to ribose, the sugar found in RNA.

* The sugar-phosphate backbone is a crucial structure in DNA. It provides the framework for the nucleotide bases (adenine, guanine, cytosine, and thymine) to attach, forming the genetic code.

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