Cytogenetics is the study of chromosomes and chromosome abnormalities. This website, created by staff at the University of Washington's Department of Pathology, offers visitors "the opportunity to see what chromosomes look like under the microscope and how abnormalities of chromosomes are identified." Those persons who might need a refresher on what a chromosome is can click on a brief description before continuing to explore the site. On the left-hand side of the page, visitors can look three sections: Cytogenetic Abnormalities, Mammal Examples, and Methods of Chromosome Visualization. The Cytogenetic Abnormalities area is a good place to start, as it describes conditions such as Klinefelter's syndrome and Trisomy 21. Moving along, the Methods of Chromosome Visualization area includes detailed explanations and materials on banding patterns along different chromosomes.