Question

Take three test-tubes. Fill each of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?

Answer 1

Living organisms release CO2 during respiration whereas plant utilize CO2 for photosynthesis. So, the test tube A will have the highest concentration of carbon dioxide because the carbon dioxide as it comes only by respiration of snail. In test tubes B and C, a part of the carbon dioxide is utilized by the plant for photosynthesis and hence there is less concentration of carbon dioxide.