Final answer:
Every organism has a species-specific number of chromosomes, designated as the diploid number, or 2n. For humans, this number is 46 in somatic cells and 23 in gametes, comprising 22 autosomal chromosome pairs and one pair of sex chromosomes.
Step-by-step explanation:
Every organism has a species-specific number of chromosomes, designated as the diploid number, or 2n. In humans, this diploid number is 46, which equates to 23 pairs of chromosomes in somatic (body) cells. Each pair consists of homologous chromosomes, which include one that is inherited from each parent. Human gametes (sex cells), such as sperm and eggs, have half the number of chromosomes, 23, which is the haploid number, or n. When a sperm and egg combine during fertilization, they create a diploid zygote with a full complement of chromosomes.
Among the 23 pairs of human chromosomes, we find 22 pairs of autosomes and one pair of sex chromosomes. The autosomes are chromosomes that do not determine the sex of an individual, whereas the sex chromosomes, which are the X and Y chromosomes, do. The combination of XX results in a female, and XY results in a male.