1. Having only a single set of chromosomes.
2. Having the gametic chromosome number.

Each human gamete normally has twenty-three chromosomes, the haploid number of chromosomes, half the number of chromosomes contained in most types of cells in the body.

Male gametes are usually small and motile (spermatozoa), whereas female gametes (oocytes) are larger and nonmotile.

3. Having a single set of each chromosome in a cell or cell nucleus.

In most animals, only the gametes (reproductive cells) are haploid.