Briefly explain the difference between "breath-
ing" and "respiration".

Ineed to know why d is the correct answer asap

Which of these has happened to your food by the time it reaches your small intestine? a. all the macromolecules have been broken down completely. b. lipids and starches have been partially broken down. c. starches and proteins have been partially broken down. d. proteins and lipids have been broken down into subunits.

Nucleic acids offer variability because they contain alternate forms of genes called .