What is the function of peristalsis?
When does the first step of digestion usually occur?
Food enters the human body through the _____.
Digestion begins in the mouth with chewing and food mixing with
Order the following steps in the digestion process.
Food is digested
Nutrients and water in the food are absorbed
Food is ingested
Undigested food is eliminated
Using complete sentences, explain why is it necessary to have both mechanical and chemical digestion?
Using a complete sentence, explain how the respiratory system and the skin play a role in in the excretory system.
Absorption in the small intestines occurs through the walls of fingerlike projections called