Answer:It is known as a concentration gradient which in diffusion will always flow from ares of high concentration to areas of low concentrations
So i believe the answer to this is A.
Explanation:
<span>hierarchical is the broadest categories in the classification of life is called.</span>
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.
