Take three test-tubes. Fill 3/4th of each with water. Label them A, B and C. Keep a snail in the 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?
Tube A: Only snail.
Tube B: Only water plant.
Tube C: Snail + Water Plant.
Test-tube C would have the highest concentration of carbon dioxide (CO2).
Test tube A would have the highest concentration of carbon dioxide (CO2) because test tube A contains snail that inhale dissolved oxygen and exhale CO2. Hence, CO2 concentration increases in test tube A.
Test tube B contains a water plant which takes in CO2 for photosynthesis and gives out O2. Hence, more O2 concentration is found in test tube B. Test tube C contains both a water plant and a snail. Snail release CO2 which is utilized by the water plant for food synthesis and O2 released by the plant is utilized by snail for respiration.
Therefore, test tube B and C have less amount of CO2 concentration as compared to test tube A.