How does the concentration of oxygen produced during photosynthesis affect fish living in a pond?

• A. Higher oxygen concentration increases fish survival by supporting their respiration.
• B. Lower oxygen concentration has no effect on fish because they do not use oxygen.
• C. Lower oxygen concentration increases the rate of photosynthesis in fish.
• D. Higher oxygen concentration causes fish to suffocate due to oxygen toxicity.

Answer: (A)

Verified step by step guidance

1. Understand the role of oxygen in fish survival: Fish rely on oxygen dissolved in water for cellular respiration, which is essential for energy production and survival.
2. Review the process of photosynthesis: Photosynthesis in aquatic plants and algae produces oxygen as a byproduct, which is released into the water and increases the dissolved oxygen concentration.
3. Analyze the impact of higher oxygen concentration: Higher oxygen levels in the pond support fish respiration, improving their survival and overall health.
4. Evaluate the incorrect options: Fish do use oxygen for respiration, so the statement 'Lower oxygen concentration has no effect on fish because they do not use oxygen' is incorrect. Fish do not perform photosynthesis, so 'Lower oxygen concentration increases the rate of photosynthesis in fish' is also incorrect. Lastly, oxygen toxicity is rare in natural pond environments, making 'Higher oxygen concentration causes fish to suffocate due to oxygen toxicity' incorrect.
5. Conclude with the correct answer: Higher oxygen concentration increases fish survival by supporting their respiration, as it provides the necessary oxygen for their metabolic processes.