Chemical analysis has shown that the number of adenine molecules in a DNA sample is always the same as the number of molecules of ............. .

Explanation

To solve the question regarding the relationship between adenine and another molecule in DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding DNA Structure**:
- DNA is composed of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
- In DNA, adenine is a purine base, while thymine is a pyrimidine base.

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