The human genome may be a complete set of macromolecule sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and during a small DNA molecule found within individual mitochondria. These are usually treated separately because of the nuclear genome, and therefore the mitochondrial genome. Human genomes include both protein-coding DNA genes and noncoding DNA. Haploid human genomes, which are contained in germ cells (the egg and sperm gamete cells created within the meiosis phase of amphimixis before fertilization creates a zygote) consist of three billion DNA base pairs, while diploid genomes (found in somatic cells) have twice the DNA content. While there are significant differences among the genomes of human individuals (on the order of 0.1% due to single-nucleotide variants and 0.6% when considering indels), these are considerably smaller than the differences between humans and their closest living relatives, the bonobos and chimpanzees (~1.1% fixed single-nucleotide variants and 4% when including indels).
