Can you list your description options and I’ll help you from there?
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.
Just as they do in most ecosystems, decomposers feed off of dead or decaying matter, recycling it back into the ecosystem for plants to receive essential nutrients and to.. basically, de-clutter the world.
The answer is that they treat bacterial infections.
