Across
- 2. Tiny air sacs in lungs where gas exchange happens (8 letters)
- 4. Organism that breathes through skin (9 letters)
- 5. Gas produced during respiration (13 letters)
- 7. Gas taken in by humans during breathing (6 letters)
Down
- 1. Process of breaking down food to release energy (11 letters)
- 3. Organ in humans responsible for gas exchange (4 letters)
- 6. A gas which we use to breathe (6 letters)