Question

The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both Test-tubes are kept in sunlight. Answer the questions that follow :

(i) Name the physiological process that releases the bubbles of oxygen. 

(ii) Explain the physiological process as mentioned above in Q.2 (a) (i).

(iii) What is the purpose of keeping a snail in test-tube 'B' ?

(iv) Why does test-tube 'B' have more bubbles of oxygen ?

(v) Give an example of a water plant that can be used in the above experiment.

(vi) Write the overall chemical equation for the above process.

Answer 1

(i) Photosynthesis

(ii) Photosynthesis is the process by which living plant cells, containing chlorophyll, produce food substances (glucose and starch) from CO₂ and water try using light energy. 

(iii) To increase the rate of photosynthesis by releasing CO₂. 

(iv) When snail respires, concentration of CO₂ increases which enhances the rate of photosynthesis. 

(v) Hydrilla

(vi)