Given a scientific question, generate a correct answer to it.

Input: Consider Input: In atherosclerosis, thickening of an arterial wall due to this can restrict blood flow through the artery?

Output: plaque formation

Input: Consider Input: Many objects have color because they contain what?

Output: pigments

Input: Consider Input: Some mutations lead to new versions of proteins that help organisms adapt to changes in their environment and are essential for evolution to occur. what are these mutations known as?
Output: beneficial mutations