Question

The diagram alongside 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 follows.

(iv) Why does test tube $B$ has more bubbles of oxygen?

Answer 1

• The process being studied here is photosynthesis.
  
• Photosynthesis is the process by which green plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of glucose.
  
• Test tube $B$ has more bubbles of oxygen because the snail while respiring releases carbon dioxide which is used by green plant for the process of photosynthesis and thus due to high rate of photosynthesis, the formation of oxygen will occur more.
  
• As a result, due to increased oxygen in test tube $B$, bubbles will be more.