B. Protistans, a group thought to have given rise to other eukaryotic cells
A. Sound is a form of mechanical energy
<span>Some mutations don't have any noticeable effect on the phenotype of an organism. This can happen in many situations: perhaps the mutation occurs in a stretch of DNA with no function, or perhaps the mutation occurs in a protein-coding region, but ends up not affecting the amino acid sequence of the protein.</span>