Answer:
Point mutations can cause serious changes to an organism if they change the way a protein works. A mutation in DNA alters the mRNA, which in turn can alter the amino acid chain. ... And a base substitution can also cause a silent mutation, in which the protein's function doesn't change at all.
Answer:
B. Sternum
Explanation:
The sternum (or breastbone) is a flat bone in the thorax's anterior area. It has a 'T' shape and is located in the center of the chest. The sternum, which is part of the bony thoracic wall, protects the internal thoracic viscera, such as the heart, lungs, and oesophagus.
Here is a picture from the internet.