Human Body Systems Quiz

Grade 6 · Science · Quiz

Test your knowledge of the major organ systems and how they work together.

Questions

1. Which organ is the main pump of the circulatory system?

   1. Liver
   2. Lung
   3. Heart
   4. Kidney
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   Answer: Heart

   The heart is a muscular organ that pumps oxygenated blood to the body and deoxygenated blood to the lungs.

2. The small intestine is where most nutrient absorption occurs.

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   Answer: True

   Most digestion and nutrient absorption occurs in the small intestine, which is about 6 meters long.

3. What is the primary function of the respiratory system?

   1. Break down food into nutrients
   2. Exchange oxygen and carbon dioxide
   3. Filter blood
   4. Produce hormones
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   Answer: Exchange oxygen and carbon dioxide

   The respiratory system brings O2 into the body and removes CO2 through breathing and gas exchange in the alveoli.

4. The ___ system includes bones and cartilage that give the body structure and protect organs.

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   Answer: skeletal

   The skeletal system's 206 bones form the body's framework, support soft tissues, protect organs like the brain and heart, and anchor muscles.

5. Which blood vessels carry blood AWAY from the heart?

   1. Veins
   2. Capillaries
   3. Arteries
   4. Alveoli
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   Answer: Arteries

   Arteries carry oxygenated blood away from the heart under high pressure. Veins return blood to the heart.

6. The liver is part of the digestive system.

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   Answer: True

   The liver produces bile to help digest fats, detoxifies the blood, and stores glycogen for energy — making it a key digestive organ.

7. What is the role of the nervous system?

   1. Pump blood through the body
   2. Control and coordinate body activities
   3. Absorb nutrients from food
   4. Produce movement by contracting
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   Answer: Control and coordinate body activities

   The nervous system (brain, spinal cord, nerves) collects sensory information and sends motor commands to control all body systems.

8. Oxygen enters the blood through tiny air sacs in the lungs called ___.

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   Answer: alveoli

   Alveoli are microscopic balloon-like sacs in the lungs. Their thin walls and rich blood supply allow rapid gas exchange.

9. Which system works directly with the skeletal system to create body movement?

   1. Digestive system
   2. Nervous system
   3. Muscular system
   4. Circulatory system
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   Answer: Muscular system

   Muscles attach to bones via tendons. When muscles contract, they pull on bones to produce movement.

10. An adult human has about 206 bones in their body.

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    Answer: True

    Newborns have about 270 bones; many of these fuse during childhood and adolescence until we end up with 206 in adulthood.

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