An experimental set-up shown below was used to investigate a certain process.
After 20 minutes, a student tested the sample from the boiling tube for starch and glucose and recorded the results as shown in the table below.
| || Star|| After 20 minutes |
| Start || Absent || Absent|
| Glucose || Absent || Present|
- Explain the presence of glucose in the water sample.
- What change occurred in the volume of liquid in:
- The boiling tube
- The visking tube