1. What substances are transported in the phloem?

2. What is a 'source' in translocation?

3. In spring, what acts as the source in a potato plant?

4. Why is phloem described as transporting materials 'both up and down' the plant?

5. What is a 'sink' in translocation?

6. Define translocation. (2 marks)

7. Explain why the position of source and sink can change in a plant. Use an example in your answer. (3 marks)

8. Explain why sucrose is transported in the phloem rather than starch. (2 marks)

9. Explain why sucrose is transported rather than glucose, even though glucose is also soluble. (2 marks)

10. State two examples of plant organs that act as sinks. (2 marks)

11. A student performs a ringing experiment: A ring of bark (including phloem) is removed from a tree trunk. After several days, swelling appears ABOVE the ring. Explain why this swelling occurs. (4 marks)

12. Draw a simple diagram showing the ringing experiment with the swelling labeled. Include: (1) The ring where bark is removed, (2) The swelling above the ring, (3) Label the direction of sucrose movement before removal.

13. A student investigates translocation using aphids. Aphids insert their mouthparts into phloem and feed on phloem sap. Identify the independent variable, dependent variable, and one control variable in an experiment to test if phloem sap sugar concentration varies at different times of day. (3 marks)

14. Suggest why radioactive tracers (e.g., carbon-14 labeled sucrose) are used to study translocation in research. (2 marks)

15. A student measures the diameter of a tree trunk above and below a ringing cut after 7 days. Suggest why measuring at multiple time points (Day 1, 3, 5, 7) would improve the investigation. (2 marks)