How do the cells of people with Down syndrome differ from those of others? How might this difference arise?

Answer 1

In the case of Down syndrome, there are three copies of chromosome 21 in each cell (rather than two, which most of us have). In Mosaic Down Syndrome, not every cell is affected, but some have the triplication, and some don't.

Answer 2

down Syndrome is also called trisomy-21. This means that the person has three 21 chromosomes instead of two. In case that sentence doesn't make sense, every pair of chromosomes is labelled pair 1, pair 2, etc. So in pair 21 there are three chromosomes instead of two. This is caused by nondisjunction, which is when a pair of chromosomes fails to separate during meiosis.

Answer 3

I know that down syndrome effects the chromozomes. They are lacking one.