1. How does the CO2 I breathe out become oxygen?

Which of the following are false concerning microbes? a. microbes generate oxygen through photosynthesis.b. the primary role of microbes on the planet involves causing disease in animals and humans.c. microbes produce vitamins in the intestines.d. microbes play a role in breaking down waste and decomposing dead organisms.

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.

To be or not to be that is da question