Grade 6 Science Worksheet (Age 12): 10 Objective Exam Questions on Circulatory & Respiratory Systems

Instructions

Read each question carefully and circle the letter of the best answer.

1. What is the primary function of the heart in the circulatory system?

   A. To filter waste from the blood
   B. To pump blood throughout the body
   C. To produce new blood cells
   D. To exchange oxygen and carbon dioxide




2. Which type of blood vessel is responsible for carrying oxygen-rich blood away from the heart to the rest of the body?

   A. Veins
   B. Capillaries
   C. Alveoli
   D. Arteries




3. Which component of blood plays a crucial role in fighting off infections and diseases?

   A. Red blood cells
   B. Plasma
   C. White blood cells
   D. Platelets




4. What is the name of the large, dome-shaped muscle located beneath the lungs that contracts and relaxes to enable breathing?

   A. Trachea
   B. Diaphragm
   C. Bronchus
   D. Larynx




5. When you inhale, your body takes in oxygen. When you exhale, what is the main waste gas your body releases?

   A. Oxygen
   B. Nitrogen
   C. Carbon Dioxide
   D. Hydrogen




6. The actual exchange of gases (oxygen and carbon dioxide) in the lungs occurs in tiny, air-filled sacs called:

   A. Bronchioles
   B. The trachea
   C. Ventricles
   D. Alveoli




7. After blood becomes oxygenated in the lungs, where does it immediately travel to next?

   A. Directly to the body's cells
   B. To the liver for filtering
   C. Back to the heart to be pumped to the body
   D. To the kidneys to be cleaned




8. The right side of the heart pumps deoxygenated (oxygen-poor) blood to which destination?

   A. The brain
   B. The legs and arms
   C. The lungs
   D. The liver




9. What is the main purpose of the platelets in your blood?

   A. To carry oxygen
   B. To fight bacteria
   C. To transport nutrients
   D. To help blood clot and stop bleeding




10. Which statement best describes the relationship between the respiratory and circulatory systems?

    A. They work independently and do not affect each other.
    B. The respiratory system delivers oxygen to the circulatory system, which then transports it to the cells.
    C. The circulatory system creates oxygen, which the respiratory system then removes from the body.
    D. The respiratory system filters the blood, and the circulatory system adds nutrients.

Answer Key

1. B. To pump blood throughout the body
2. D. Arteries
3. C. White blood cells
4. B. Diaphragm
5. C. Carbon Dioxide
6. D. Alveoli
7. C. Back to the heart to be pumped to the body
8. C. The lungs
9. D. To help blood clot and stop bleeding
10. B. The respiratory system delivers oxygen to the circulatory system, which then transports it to the cells.