Final answer:
The sugar in RNA (ribose) has a hydroxyl group at the 2' carbon, while the sugar in DNA (deoxyribose) has a hydrogen atom at the 2' carbon.
Step-by-step explanation:
The structural difference between the sugar found in RNA and the sugar found in DNA is the presence of a hydroxyl group at the 2' position on the pentose sugar. Specifically, ribose, which is the sugar in RNA, has a hydroxyl group (-OH) at the 2' carbon. Conversely, deoxyribose, the sugar found in DNA, has only a hydrogen atom (H) at the same position, hence the prefix 'deoxy-' indicating the absence of an oxygen atom. Both ribose and deoxyribose are D-sugars in five-membered cyclic form and part of the nucleotides that make up the genetic material, with ribose contributing to the single-stranded structure of RNA and deoxyribose to the double helix structure of DNA.