Human Body Systems Quiz

Grade 7 · Science · Quiz

10-question quiz on the major organ systems and how they function together.

Questions

1. Which organ pumps blood throughout the circulatory system?

   1. Lungs
   2. Liver
   3. Heart
   4. Kidneys
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   Answer: Heart

   The heart is a muscular pump that contracts roughly 100,000 times a day, circulating about 5 liters of blood per minute through the body.

2. The respiratory system is responsible for digesting food.

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   Answer: False

   The respiratory system's job is gas exchange — getting oxygen into the blood and removing CO₂. Digestion is handled by the digestive system.

3. The windpipe that carries air to the lungs is called the ___.

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   Answer: trachea

   The trachea (windpipe) extends from the larynx in the throat down to where it splits into two bronchi, one leading to each lung.

4. What is the main function of red blood cells?

   1. Fight infection
   2. Carry oxygen
   3. Digest nutrients
   4. Produce hormones
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   Answer: Carry oxygen

   Red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and releases it to cells throughout the body.

5. The skeletal system protects vital organs like the brain and heart.

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   Answer: True

   The skull protects the brain, the ribcage protects the heart and lungs, and the vertebral column protects the spinal cord.

6. Which part of the digestive system reabsorbs water from waste material?

   1. Stomach
   2. Small intestine
   3. Esophagus
   4. Large intestine
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   Answer: Large intestine

   The large intestine's primary function is to absorb water from undigested material, turning liquid waste into solid feces before elimination.

7. The brain and spinal cord together make up the ___ nervous system.

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   Answer: central

   The CNS (brain + spinal cord) is the command and processing center. The peripheral nervous system includes all the nerves branching out to the rest of the body.

8. Hormones are chemical messengers produced by the endocrine system.

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   Answer: True

   The endocrine system produces hormones like insulin, adrenaline, and growth hormone, which travel through the bloodstream to regulate many body functions.

9. What type of blood vessel connects arteries to veins?

   1. Capillaries
   2. Arterioles
   3. Venules
   4. Lymph nodes
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   Answer: Capillaries

   Capillaries are the tiniest blood vessels. They are one cell thick, allowing nutrients, oxygen, and waste products to pass between blood and body cells.

10. How many bones does the average adult human skeleton have?

    1. 150
    2. 206
    3. 270
    4. 300
    Show answer

    Answer: 206

    Adults have 206 bones. Infants are born with about 270 bones, but many fuse together during growth.

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