Suppose you are studying the transport of a certain polar molecule across the plasma membrane of cells in culture. over a period of time, you measure the concentration of a polar molecule inside and outside of the cells. you find that the concentration of the molecule is lower in the cell but is gradually increasing. you also measure the atp concentration inside the cell and find that it is not changing. which of the following is probably responsible for the transport of this polar substance into the cell? a) active transport
b) endocytosis
c) facilitated diffusion
d) secondary active transport
e) simple diffusion

the answer to your question is b

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.