Explanation:
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg.
In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
In the remaining cases, the error occurs after fertilization, as the embryo grows.
Answer:
Fires, volcanoes, and weathering
<span>Carbon-based macromolecules are found in all life forms.</span>
Length times width times highth
