Across
- 3. The part of the respiratory system that carries air to the lungs (4 letters).
- 4. The organ in mammals where gas exchange occurs (5 letters).
- 5. The organ that helps fish absorb oxygen from water (5 letters).
- 6. The organ that takes in air in humans and many other animals (5 letters).
Down
- 1. The part of a plant responsible for gas exchange (4 letters).
- 2. The gas released as a waste product of aerobic respiration (8 letters).