20 POINTS!
It's for a quiz so answer quick

How does natural selection change thephenotypes within a population over time?

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.

Explain why the plants cortex would serve as the best food source for animals