Cytologists had been studying chromosome behavior since the late 19th century. Why did it take until 1956 to figure out the correct human chromosome number, thanks to Joe Hin Tjio and Albert Levan?

Human biological sex is determined by the sex chromosomes X and Y. In most cases, females possess two X chromosomes, while males have one X and one Y. However, there is some evidence that the Y ...

(b) A clone selected on the basis of band location is used in FISH analysis to map the breakpoint of a translocation involving chromosomes 11 and 19 in a patient with multiple congenital ...