How can two physically healthy parents produce a child with Down syndrome and a second child with Klinefelter syndrome?

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.

Describe the function of the endomembrane system? what organelles are involved?

Why is it important to study each branch of earth science?