1. A phosphate group: This is a molecule containing phosphorus and oxygen atoms.

2. A sugar: This is a 5-carbon sugar molecule. In DNA, the sugar is deoxyribose; in RNA, the sugar is ribose.

3. A nitrogenous base: This is a ring-shaped molecule containing nitrogen. There are five common nitrogenous bases: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).

So, the combination found in a nucleotide is:

* Phosphate group + Sugar + Nitrogenous base

For example, one nucleotide in DNA could be composed of a phosphate group, a deoxyribose sugar, and the nitrogenous base adenine (A).