A karyotype is the complete set of chromosomes of an individual, including their sizes, numbers, and shapes/02%3A_Chromosomes_Mitosis_and_Meiosis/2.05%3A_Karyotypes_Describe_Chromosome_Number_and_Structure). It is a laboratory-produced image of a persons chromosomes isolated from an individual cell and arranged in numerical order. To obtain a karyotype, scientists take a picture of the chromosomes from one cell, cut them out, and arrange them using size, banding pattern, and centromere positions as guides. Karyotypes can be used to look for abnormalities in chromosome number or structure. They can also be used for many purposes, such as studies of chromosomal iterations in prenatal diagnostics or tumor studies, to understand cellular function, taxonomic relationships, and providing information about past evolutionary events. In humans, the typical karyotype contains 22 pairs of autosomal chromosomes and one pair of sex chromosomes.