The human male gamete, also known as a sperm cell, contains 23 chromosomes in total. Humans have 22 chromosome pairs as well as two sex chromosomes, for a total of 46 chromosomes. The gamete produced by each sex contains half, or 23, of these chromosomes.
Chromosomes are responsible for carrying hereditary traits that make up the composition of human bodies from head to toe. Occasionally, a gamete carries extra chromosomes or not enough chromosomes. The zygote that results from a pairing of such gametes is typically not viable, but in some situations, the child survives, living with a genetic disorder such as trisomy 21, also known as Down syndrome.