Final answer:
Hydrogen bonds are responsible for holding complementary bases together in DNA, with adenine pairing with thymine and cytosine pairing with guanine to maintain the structure of the double helix and encode the genetic information.
Step-by-step explanation:
Hydrogen bonds hold the complementary bases together in DNA. Specifically, adenine (A) always pairs with thymine (T) forming two hydrogen bonds, while cytosine (C) pairs with guanine (G) forming three hydrogen bonds. This pairing is crucial for the DNA's double-helix structure because it maintains a consistent distance between the two DNA strands, ensuring the molecule's stable, uniform shape.
The complementary base pairs are like the rungs of a ladder, with adenine and thymine as well as cytosine and guanine always bonding together due to their specific shape and chemical properties, resulting in the genetic code being represented by the particular sequence of bases.