IB skill practice

Explain transport systems in animals and plants

Paper 1, Paper 2 5 marks Difficulty 3

Explain phloem translocation

A plant diagram in a reproductive biology class shows sucrose moving from a leaf to a growing root. Name the tissue and explain why movement can be source to sink. Use the diagram labels, physiology pathway, feedback loop, or data values before answering. Enter the answer and choose the interpretation that best matches the biological evidence.

Worked practice: biological evidence and answer

Use the labelled biological evidence first, then connect it to the final answer.