Describe what happens to insulin and glucagon secretions
duringfasting, and the resulting metabolic changes that occur at
thattime.

Explanation:

The blood glucose levels begins to low or drop in fasting condition, this leads to the decrease in secretion of insulin hormone. This further leads to the rise in glucagon secretion.

The glucagon is secreted by the α cells of the pancreas corresponding to the low blood sugar level. The liver is the target organ for glucagon. It stimulates the glycogen breakdown and inhibits the glycogen synthesis.  

The glucagon stimulates gluconeogenesis in the liver. The glucose formed by the hydrolysis of the glucose 6-phosphate is released from the liver. This process maintains the blood sugar levels in the fasting condition.  

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.