Definition of Chromosome, Y
Chromosome, Y: The sex chromosome found in normal males, together with an X chromosome. Once thought to be a genetic wasteland, the Y chromosome is now known to contain at least 20 genes. Some of these genes are unique to the Y chromosome, including the male-determining gene and male fitness genes that are active only in the testis and that are thought to be responsible for the formation of sperm. Other genes on the Y chromosome have counterparts on the X chromosome, are active in many body tissues, and play crucial 'housekeeping' roles within cells.
Last Editorial Review: 3/19/2012
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?