Which statement about the salamander-fern scenario best describes the reasoning used in the material?

Which statement about the salamander-fern scenario best describes the reasoning used in the material?

• A. The fern uses oxygen produced by the plant to survive
• B. The plant produces oxygen that the salamander uses
• C. The salamander with the fern would survive due to oxygen produced by the plant and carbon dioxide involved
• D. Neither would survive

Answer: (C)

Gas exchange between a photosynthesizing organism and an animal is a common way to show interdependence in ecosystems. The fern performs photosynthesis, releasing oxygen into the air. The salamander can breathe that oxygen, which helps it survive. Meanwhile, the salamander exhaled carbon dioxide is used by the fern for photosynthesis, continuing the cycle. So the scenario is best described as the salamander surviving because of oxygen produced by the fern, with carbon dioxide from the salamander involved in fueling the fern’s photosynthesis. This captures the full, reciprocal relationship: oxygen supports the animal, and CO2 supports the plant.

Gas exchange between a photosynthesizing organism and an animal is a common way to show interdependence in ecosystems. The fern performs photosynthesis, releasing oxygen into the air. The salamander can breathe that oxygen, which helps it survive. Meanwhile, the salamander exhaled carbon dioxide is used by the fern for photosynthesis, continuing the cycle. So the scenario is best described as the salamander surviving because of oxygen produced by the fern, with carbon dioxide from the salamander involved in fueling the fern’s photosynthesis. This captures the full, reciprocal relationship: oxygen supports the animal, and CO2 supports the plant.