Answer:
Explanation:
It means that chromosome 21 has a third partial or complete copy of chromosome 21. The symptom severities vary somewhat.
Answer:
There are three set of chromosome 21
Explanation:
Trisomy signifies presence of abnormal three chromosomes instead of two.
Down syndrome is also known as trisomy 21 because there are three chromomose -21 rather than two.
There are 46 chromosome in a normal human being which constitutes 23 pairs of chromosome. However, a person suffering from down syndrome has 47 chromosome with an extra chromosome -21.
