How do certain base combine to form complete rung ladder?

In the context of DNA structure, certain bases combine to form a complete rung of the ladder through complementary pairing. Adenine (A) pairs with thymine (T), while cytosine (C) pairs with guanine (G). These pairs are held together by hydrogen bonds, creating the "rungs" of the double helix ladder. The sequence of these base pairs encodes genetic information, while the sugar-phosphate backbone forms the sides of the ladder.