Across
- 3. What is a gas that humans do not need for survival?
- 6. Respiration is ________________ reaction to release energy.
- 8. Plants have tiny openings called ____________ which helps in the exchange of gases.
- 9. The lungs contain air _____ that help increase the surface area to take in more air.
- 10. Our diaphragm moves _________ when we inhale.
Down
- 1. Water enters the mouth of the fish and flows over the _______.
- 2. Breathing is a _____________ action.
- 4. Air is generally taken in through the _______.
- 5. Our diaphragm moves _________ when we exhale.
- 6. If carbon dioxide is present, limewater will turn __________.
- 7. The main function of the respiratory system is for the ______________ of gases with the surroundings.