Question

1. which is not a part of the respiratory system? a. alveoli b. lungs c. trachea d. esophagus 2. how does the diaphragm aide in breathing? a. when the diaphragm contracts, the lungs expand and allow oxygen to enter b. when the diaphragm relaxes, the lungs expand and allow oxygen to enter c. the diaphragm does not work with the respiratory system 3. how do plants benefit from human respiration? a. plants need oxygen to survive b. plants need water to survive c. plants need carbon dioxide to survive d. plants need nitrogen to survive

Explanation:

1. The esophagus is part of the digestive system, not the respiratory system. Alveoli are in the lungs and are the site of gas - exchange, lungs are the main organs of respiration, and trachea is the airway that leads to the lungs.
2. When the diaphragm contracts, it moves downward, increasing the volume of the thoracic cavity. This causes the lungs to expand and air (oxygen) to enter.
3. Humans exhale carbon - dioxide during respiration. Plants use carbon - dioxide in the process of photosynthesis to produce food and oxygen.

Answer:

1. D. Esophagus
2. A. When the diaphragm contracts, the lungs expand and allow oxygen to enter
3. C. Plants need carbon dioxide to survive