What macromolecules help to make the cell membrane

Me with biology endocrine system crossword also image left i need with hw

Aplant may open end close its stomata to prevent excess water loss and maintain

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons