Falsecolour light micrograph of a normal trypsinleishman banded female karyotype, the full complement of female chromosomes arranged in numbered homologous pairs. The chromosomes are presented in this manner by matching up unpaired chromosomes photographed during the metaphase stage of cell division. Each member of a homologous pair is similar in length & banding pattern. Male & female sets differ only in the sex pair (bottom right); a male would be labelled XY instead of XX. The nucleus of each human cell contains a total of 46 chromosomes, 23 of maternal and 23 of paternal origin.