Why are fatty acids better than glycogen for storing large amounts of chemical energy?

The fatty acids or fats provide a large amount of energy about 9 kcal g⁻¹ than glycogen which provides about t 4 kcal g⁻¹.

This large difference in the calorific value is due to the nature of the fatty acids as these are much more reduced than the glycogen as well as they are stored in the body in anhydrous form due to non-polar triacylglycerols in the adipose cells. The carbohydrates are highly hydrated compounds as they contain polar molecules in their structure which binds the water molecules.

So, the evolution selected the fatty acids over glycogen for the production of the chemical energy.

not sure if this is what you'r looking for nnew= nold

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.