A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. Karyotypes also describe the chromosomes count of an organism and the appearance of these chromosomes under the microscope. Cell which lack cell cycle control are often cancerous cells and they look different under the microscope compared to the normal cells. Cancerous cells will look different under the microscope in term of number of chromosomes, size, length, positioning and general appearance.
