Lesson Check: Obtaining Energy and Removing Waste

When does the first step of digestion usually occur?

• A) when the organism discovers the food
• B) when the food is chewed
• C) when the food is swallowed
• D) when the nutrients are absorbed

Food enters the human body through the _____.

• A) esophagus
• B) mouth
• C) intestine
• D) liver

Digestion begins in the mouth with chewing and __________________ beginning to break down food.

• saliva
• esophagus
• liver
• stomach

• A) C, D, A, B
• B) C, A, D, B
• C) A, C, D, B
• D) A, B, C, D

Chewing is what kind of digestion?

• mechanical digestion
• chemical digestion

What is the function of peristalsis?

• A) to move food through the digestive system
• B) to remove excess liquid from the body
• C) to chemically digest food to release nutrients
• D) to absorb nutrients into the blood

The esophagus is a tube that connects the

• A) mouth to the stomach
• B) mouth to the large intestine
• C) mouth to the small intestine
• D) stomach to the large intestine

What type of digestion breaks down food into small pieces?

• A) mechanical digestion
• B) chemical digestion
• C) absorption digestion
• D) peristalsis

The kidneys, skin, and lungs are each part of the __________________ system.

• respiratory
• excretory
• digestive
• nervous

What is the main function of the excretory system?

• A) to collect and remove wastes from the body

• B) to strengthen skeletal muscles

• C) to protect the nervous system

• D) to bring oxygen to body cells