C. Mutagens causes mutations.
You're gonna have to give us a picture to support your question..
The neuron releases chemical messengers. Otherwise, there would be no 'signal transduction' in the postsynaptic cell. So, your answer is B.
Answer: The main organ of the integumentary system is the skin.
Explanation: The skin regulates body temperature, keeps germs from entering your body, and produces vitamin D to help absorb calcium.
Http://www.collective-evolution.com/2014/07/07/new-study-finds-88-percent-of-earths-ocean-surface-no...
This should be of use here.
