Cells that do not have pairs of chromosomes are called haploid cells. They have only one set of chromosomes, unlike diploid cells which have two sets.

Here are some examples of haploid cells:

* Gametes (sperm and egg cells): These cells are responsible for sexual reproduction. They combine to form a diploid zygote.

* Spores in plants and fungi: These cells are involved in asexual reproduction. They can develop into new organisms without fertilization.

Note: It's important to understand that the term "haploid" refers to the number of chromosome sets, not the total number of chromosomes. For example, a human gamete is haploid with 23 chromosomes, while a human somatic (body) cell is diploid with 46 chromosomes.