Unit 1 Lesson 3 Obtaining Energy and Removing Waste

What is the function of peristalsis?

• to move food through the digestive system

• 
  to remove excess liquid from the body

• to chemically digest food to release nutrients

• 
  to absorb nutrients into the blood

When does the first step of digestion usually occur?

• when the organism discovers the food

• when the food is chewed

• when the food is swallowed

• when the nutrients are absorbed

 Food enters the human body through the _____.

• 
  esophagus

• mouth

• 
  intestine

• 
  liver

Digestion begins in the mouth with chewing and (a)   beginning to break down food.

The function of the excretory system is to collect and eliminate wastes from the body and regulates the level of fluid in the body.

• True
• False

Reorder the following with the correct order of the digestion process.

• food is digested

• undigested food is eliminated

• food is ingested through mouth

• nutrients and water in the food are absorbed

It is not necessary to have both mechanical and chemical digestion.

• True
• False

Chewing is _____ digestion.

• chemical

• mechanical

Absorption in the small intestines occurs through the walls of fingerlike projections called _____.

• glands

• enzyme

• villi

• digestion

The nutrients in food enter and are used by the body. This happens through the processes of digestion.

• True
• False