The human genome is the genome of Homo sapiens.
It is made up of 23 chromosome pairs with a total of about 3 billion DNA base pairs.
There are 24 distinct human chromosomes: 22 autosomal chromosomes, plus the sex-determining X and Y chromosomes.
Chromosomes 1-22 are numbered roughly in order of decreasing size.
Somatic cells usually have one copy of chromosomes 1-22 from each parent, plus an X chromosome from the mother, and either an X or Y chromosome from the father, for a total of 46.
There are an estimated 20,000-25,000 human protein-coding genes.
The estimate of the number of human genes has been repeatedly revised down from initial predictions of 100,000 or more as genome sequence quality and gene finding methods have improved, and could continue to drop further.