Final answer:
The bonds that link adjacent nucleotides in both RNA and DNA are phosphodiester bonds, which are a specific type of covalent bond forming the backbone of the nucleic acid molecule.
Step-by-step explanation:
The type of bonds that link adjacent nucleotides in both RNA and DNA are phosphodiester bonds. These bonds are a type of covalent bond. In the structure of nucleic acids, the phosphodiester bond forms when the phosphate group attached to the 5' carbon of the sugar of one nucleotide connects with the hydroxyl group of the 3' carbon of the sugar of the next nucleotide. This linkage results in a recurring 5'-3' phosphodiester bond that creates the backbone of the nucleic acid chains, providing stability to the overall molecule.
It's important to note that in DNA, hydrogen bonds are also present, but they play a different role. They form between complementary nitrogenous bases (adenine to thymine, or cytosine to guanine) across the two strands of the DNA double helix. However, these hydrogen bonds are not responsible for linking nucleotides along the same strand; that role is exclusively held by the phosphodiester bonds.