Female chromosomes. Enhanced light micrograph of a normal female karyotype, the full complement of human female chromosomes arranged in numbered pairs. The chromosomes are presented in this manner by matching up unpaired chromosomes during the metaphase stage of cell division. Here they appear as homologous pairs similar in length and banding pattern. Male and female sets differ only in the sex chromosomes (bottom right): a male would be labelled XY instead of XX. The nucleus of each human cell contains 46 chromosomes in total, 23 of maternal & 23 of paternal origin. A normal female karyotype is written: 46,XX.