Which of the following best describes a process that helps a cell maintain homeostasis without requiring energy to be used? 1.Channel proteins provide a passage for molecules to cross the membrane via facilitated diffusion.
2.Membrane carrier proteins help substances enter the cell against a concentration gradient.
3.Pieces of the cell membrane for vesicles circulate around extracellular materials during endocytosis.
4.Protons are pumped out of the cell to create a voltage across the cell membrane.

answer; both surfaces of the membrane are nonpermeable

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.