Idiogram. Artwork of an idiogram representing the chromosomes of a healthy human male. This is a representation of the banding patterns seen in metaphase chromosomes during meiotic cell division. The bands are produced by dyes. The relative distances between these bands are always the same for an individual chromosome, so this is a useful way of identifying a particular chromosome. A healthy male Y chromosome (lower right), for instance, always has the pattern seen here. Chromosomes are long strands of DNA (deoxyribonucleic acid) which carry the genes which determine an individual's characteristics.