Cell membranes A. separate the inside of the cell from the exterior. B. selectively allow certain materials to cross the membrane. C. contain phospholipids and proteins D. are identical across cell types. E. Both A and B. F. Both A and C G. Choices A, B, and C. H. Choices, A, B, and D. All of the choices are correct. Solution Cell Membrane- A. Seperate the inside of the cell from the exterior. B.Selectively allow certain materials to cross the membrane. C.Contain phospholipids and proteins. D.Are identical across cell types E.Both A and B F.Both A and C G. Choices A,B and C H. Choices A,B and D I. All of the choices are correct ANSWER- I. ALL OF THE CHOIUCES ARE CORRECT. (Phospholipids form a thin, flexible, sheet while the proteins float in the phospholipid sheets like iceberg.The phospholipids are arranged in bilayer (hydrophilic head in the intracellular fluid or hydrophobic tail in the extracellular fluid.) (for prokaryotes,membrane contain no carbohydrate and lacks sterols whereas for eukaryotic, the plasma membrane contain carbohydrate and sterol that serve as receptor.).