Answer:
Number of protons
Explanation:
Any particular element can always be identified by its number of protons.
Nucleus has genetic material (DNA) inside it, so it commands the cell about how it has to be function......
They are sandwiched between two layers of heads. Recall that the heads are hydrophilic therefore they will always be on the outside and the tails are hydrophobi therefore they willl always be away from water, there fore sandwiched. I'm a bio major, hope I helped :)
