What is the structure of a chromosome? Why does the total number of chromosomes in a cell matter? Learn how chromosomes self-organize within single cells, and how these patterns help us detect ...

Today, most karyotypes are stained with Giemsa dye ... with the exceptions of chromosomes 21 and 22, the former actually being the smallest autosome. The sex chromosomes are generally placed ...

In the size range of chromosomes 21, 22 and Y there were 6 chromosomes ... with no significant number of cells with any other karyotype. Note the total number of 47, 1 X chromosome, and 2 Y ...

What is Down syndrome Down syndrome, also known as Trisomy 21, is a genetic disorder caused by an extra copy of chromosome 21 ... and a chromosomal analysis (karyotype test) help confirm the ...