These changes can<span> be caused by environmental factors such as ultraviolet radiation from the sun, or</span>can<span> occur if an error is made as </span>DNA<span> copies itself during cell division. Acquired </span>mutations<span> in somatic cells (cells other than sperm and egg cells) cannot be passed to the next generation.</span>
So that they don't explode.
AKA with a thing called osmosis (transportation of water through cells.)
