Question

The amount of adenine is always equal to the amount of ______ in DNA.

Options

• cytosine

• uracil

• guanine

• thymine

Answer 1

The amount of adenine is always equal to the amount of thymine in DNA.

Explanation:

In a double-stranded DNA molecule, the amount of adenine (A) is always equal to the amount of thymine (T) because they are complementary base pairs that specifically bind to each other using two hydrogen bonds. This 1 : 1 ratio is a fundamental part of Chargaff’s Rules, which state that the total amount of purines always equals the total amount of pyrimidines within a DNA sample.