A human gamete contains 23 unpaired chromosomes. For example, in a spermatozoa, there are 22 unpaired autosomes and one sex chromosome, either an X chromosome for a female or a Y chromosome for a male.
Gametes are produced through a specific type of cell division called meiosis, according to 3DScience.com. In somatic cells, or non-sex cells, humans have 23 paired chromosomes for a total of 46 chromosomes. During meiosis, only one chromosome from each pair is transferred to the gamete. Therefore, when the two gametes combine during conception, there are 23 chromosomes from the female egg and 23 chromosomes from the male sperm in order to give the offspring a total of 46 chromosomes.