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.

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

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.
  
• Snail in test tube $B$ will exhale carbon dioxide by the process of respiration and hence provide carbon dioxide essential for the photosynthesis process.