By dividing the amount of work done by the time it takes to do it; by dividing energy used in a given period by time.
It seems like the answer is "neurotransmitters".
Answer:
Classification systems vary with the taxonomist.
Viruses are tinier than bacteria. ... All viruses have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells.
