An<unk>  is any chromosome that is not a sex chromosome. The members of an<unk>  pair in a diploid cell have the same morphology, unlike those in allosome pairs which may have different structures. The DNA in<unk> s is collectively known as atDNA or auDNA. For example, humans have a diploid genome that usually contains 22 pairs of<unk> s and one allosome pair (46 chromosomes total). The<unk>  pairs are labeled with numbers (1–22 in humans) roughly in order of their sizes in base pairs, while allosomes are labelled with their letters. By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations of XYY, XXY, XXX, XXXX, XXXXX or XXYY, among other Salome combinations, are known to occur and usually cause developmental abnormalities.<unk> s still contain sexual determination genes even though they are not sex chromosomes. For example, the SRY gene on the Y chromosome encodes the transcription factor TDF and is vital for male sex determination during development. TDF functions by activating the SOX9 gene on chromosome 17, so mutations of the SOX9 gene can cause humans with an ordinary Y chromosome to develop as females. All human<unk> s have been identified and mapped by extracting the chromosomes from a cell arrested in metaphase or prometaphase and then staining them with a type of dye (most commonly, Giemsa). These chromosomes are typically viewed as karyograms for easy comparison. Clinical geneticists can compare the karyogram of an individual to a reference karyogram to discover the cytogenetic basis of certain phenotypes. For example, the karyogram of someone with Patau Syndrome would show that they possess three copies of chromosome 13. Karyograms and staining techniques can only detect large-scale disruptions to chromosomes—chromosomal aberrations smaller than a few million base pairs generally cannot be seen on a karyogram. Karyotype of human chromosomes Female (XX) Male (XY) center center There are two copies of each<unk>  (chromosomes 1–22) in both females and males. The sex chromosomes are different: There are two copies of the X-chromosome in females, but males have a single X-chromosome and a Y-chromosome.
Autosome
Ethosome
Sex chromosome
X chromosome
Y chromosome
Ring chromosome 15
Ring chromosome 18
Ring chromosome 22