Levels of Organization
Respiratory System
Circulatory System
Digestive System
Nervous System
Systems Working Together
100

Put these in order from smallest to largest: organ, cell, tissue, organism, organ system.

Cell → Tissue → Organ → Organ System → Organism

100

The main job of the respiratory system is to ________.

Hint: Be more specific than "to breathe."

Bring oxygen into the body and remove carbon dioxide.

100

The heart acts as what type of machine for the body?

A muscular pump

100

The main function of the digestive system is to ________. 

Hint: Be more specific than "digest."

Break down food and absorb nutrients.

100

Which body system controls and coordinates the body's activities and responses?

Nervous System

100

Which two systems work together to supply oxygen to body cells?

Respiratory and Circulatory Systems

200

This level of organization is made of similar cells working together.

Tissue

200

What is the main job of the lungs?

Take in oxygen and expel carbon dioxide.

200

The circulatory system transports these two important materials to body cells.

Oxygen and nutrients

200

Which organ uses acid and churning to break down food?

Stomach

200

The brain and spinal cord together make up what?

Central Nervous System (CNS)

200

After nutrients are absorbed in the digestive system, which system transports them throughout the body?

Circulatory System

300

The heart is an example of this level of organization.

Organ

300

What is the main job of the alveoli?

Exchange oxygen and carbon dioxide between the lungs and bloodstream.

300

Which blood vessels carry blood away from the heart?

Arteries

300

Which organ absorbs most nutrients from food?

Small intestine

300

Which brain part controls voluntary movement, senses, and thinking?

Cerebrum

300

How do the respiratory and circulatory systems work together?

The respiratory system brings oxygen into the lungs, and the circulatory system transports it to body cells.

400

A group of organs works together to digest food. What level of organization is this?

Organ system

400

A person can breathe in air, but oxygen is not entering the bloodstream. Which structure is most likely not working correctly?

Alveoli

400

Explain the difference between arteries and veins.

Arteries carry blood away from the heart; veins carry blood back to the heart.

400

Compare the jobs of the small intestine and large intestine.

The small intestine absorbs most nutrients; the large intestine absorbs water.

400

A student sees a slice of pizza and suddenly feels hungry. Which body systems are working together?

Nervous and Digestive Systems

400

How do the digestive and circulatory systems work together after you eat?

The digestive system absorbs nutrients, and the circulatory system transports them to body cells.

500

A muscle cell, muscle tissue, the heart, the circulatory system, and a human represent the five levels of organization. Put them in order from smallest to largest.

Muscle Cell → Muscle Tissue → Heart → Circulatory System → Human

500

A person's diaphragm stops working correctly. Explain how this would affect breathing and oxygen intake.

The lungs would have difficulty expanding and contracting, so less oxygen would enter the body.

500

A person's capillaries are damaged. Which important function would be affected most?

Delivering oxygen and nutrients to body tissues.

500

A person's pancreas is not producing enough enzymes. What would most likely happen during digestion?

Food would not be broken down completely, so fewer nutrients would be absorbed.

500

You touch a hot stove and pull your hand away. Explain how the nerves, spinal cord, and brain work together to make this happen.

Nerves detect the heat and send a signal through the spinal cord. 

The spinal cord helps trigger a quick response, and the brain processes the information so the person recognizes the danger.

500

Choose two body systems and explain:

-The main job of each system
-How they work together to help the body survive 

Example: The respiratory system brings oxygen into the body. The circulatory system transports oxygen to cells. Together they help cells make energy.

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