Respiration

Name: ______________________   Date: ____________

Use the clues to fill in the crossword.

Across

  1. 1. Organ that pumps blood around the body (5)
  2. 3. A heavy odorless colorless gas formed during respiration and by the decomposition of organic (13)
  3. 5. The metabolic processes whereby certain organisms obtain energy from organic molecules (11)
  4. 8. The power to do work or make things move (6)
  5. 10. Tiniest unit of living things (plural) (5)
  6. 11. Gas in the air that we need to breathe (6)

Down

  1. 2. A mature ___ ___ that contains hemoglobin to carry oxygen to the bodily tissues (plural) (13)
  2. 4. The bodily process of inhalation and exhalation (9)
  3. 6. Physical activity that keeps you fit (8)
  4. 7. Either of two saclike respiratory organs in the chest of vertebrates (plural) (5)
  5. 9. Red liquid pumped around the body by the heart (5)