What is the main difference between muscle cells and nerve cells? a. they use different genetic codes. b. they have different ribosomes. c. they contain different genes. d. they express different genes.

The main difference between muscle cells and nerve cells is they express different genes.  

Explanation:

Muscle cell and neurons are both excitable in nature both in form and also in functions. The protein that helps in muscle specific genes, in the muscle cells which differs from neurons. The nerve cell uses protein to help and transmit the message. Muscle cells contract and shows excitability. Muscle cells send excitability messages through contraction. Nerve cells helps in the transmission of "neural synapses", muscle cells can be smooth. Smooth muscle cells help in make up the internal organs.

for 8 am not sure maybe yes?

for 9 if it is asking if the male is more or less it would be less

hope i even just a little : )