A terrestrial organism has an advantage over an aquatic organism with regard to obtaining oxygen for respiration because:
- Terrestrial organisms take up oxygen from the atmosphere, where the oxygen content is high, whereas aquatic animals obtain oxygen dissolved in water.
- Air contains more oxygen than water, so terrestrial animals do not have to breathe faster to get more oxygen, unlike aquatic animals.
- Terrestrial animals do not need adaptations for gaseous exchange and can adapt to a relaxed mode of breathing.
