Biology crossword

3. the basic unit of any living thing. Some living things consist of only a single cell, while others are composed of trillions of cells
4. cords two folds of tissue in the larynx that vibrate when air passes over them and produce sound, including the basic sounds of speech.
6. breathe in.
10. to take air in and expel it out of the lungs.
13. dioxide a gas that is a waste product of cells when they burn food.
15. the movement of oxygen from the atmosphere to cells and carbon dioxide from cells to the atmosphere.
16. a flap of tissue that prevents food from going down the trachea rather than the oesophagus.
18. a disease that damages the alveoli, making it difficult to get enough oxygen.
21. a large muscle below the ribs that helps a person breathe.
23. a breathing disorder in which the air passageways in the lungs constrict, causing shortness of breath.
25. capacity the volume of air that the lungs can hold.

1. hair-like structures found in the air passageways of the respiratory system.
2. breathe out.
5. a gas in air that humans and most living things need to live.
7. tiny blood vessels.
8. one of the lung's smallest air passageways.
9. system the group of organs that take in oxygen from the air and release carbon dioxide.
11. tiny air sacs in the lungs.
12. pair of tubes between the trachea and the lungs.
14. two bag-like organs that fill most of the chest. The lungs draw in air through the trachea and bronchi.
17. the tube that carries food from the back of the throat to the stomach.
19. a cavity behind the nose and mouth that leads to the trachea and oesophagus.
20. the air passageway between the pharynx and the bronchi.
22. a part of the respiratory system between the pharynx and the trachea. It houses the vocal cords.
24. a sticky substance in the nose that traps dirt, dust and other particles.