<P> A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell . The term is also used for the complete set of chromosomes in a species or in an individual organism and for a test that detects this complement or measures the number . </P> <P> Karyotypes describe the chromosome count of an organism and what these chromosomes look like under a light microscope . Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics . The preparation and study of karyotypes is part of cytogenetics . </P> <P> The study of whole sets of chromosomes is sometimes known as karyology . The chromosomes are depicted (by rearranging a photomicrograph) in a standard format known as a karyogram or idiogram: in pairs, ordered by size and position of centromere for chromosomes of the same size . </P>

During what phase of the cell cycle are karyotypes made