Humans have 23 pairs of chromosomes, giving each cell a total of 46. This includes 22 pairs of autosomes and one pair of sex chromosomes.
According to the National Human Genome Research Institute, chromosomes are arranged in pairs inside the nucleus of each cell. Almost all of the cells in the body have a full set of chromosomes, with the exception of reproductive cells, or gametes, which carry only half a set. When two gametes cells unite during reproduction, a complete set of paired chromosomes is formed in the new cell, with half inherited from the mother and half from the father.