Biologists use the symbol "n" to represent one set of chromosomes.

Here's how it works:

* n = haploid: This means the cell has one set of chromosomes. Examples include gametes (sperm and egg cells).

* 2n = diploid: This means the cell has two sets of chromosomes. Most organisms, including humans, are diploid.

So, when you see "n" in a biological context, it signifies a single set of chromosomes.