To test how fertilizer affects tomato plants, a farmer divided a field of young tomato plants into 10 plots of equal size. the farmer then put fertilizer on half of the plots and no fertilizer on the other half of the plots. what is the control group in this experiment?

a. all the weedy plants in all the plots
b. the tomato plants in all the unfertilized plots
c. the tomato plants in all the fertilized plots
d. all the tomato plants in the field

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.