Typical images of metaphase chromosome spreads.

A. A euploid cell with 40 chromosomes. B. A hyperploid cell with 41chromosomes. C. A hyperploid cell with 43 chromosomes. D. A triploid cell with 60 chromosomes. Lines are drawn to divide the spreads into 10-chromosome blocks, with the exception of the extra chromosomes in hyperploid karyotypes, to facilitate chromosome counting.