Biology · May / June 2019 · Paper 11 · Question 7

A plant has leaves with both green and white areas. One of its leaves is partly covered with aluminium foil which blocks light. The plant is then placed under a lamp for 24 hours. After this time, discs are cut from the areas of the leaf shown, and tested with iodine solution. Which of the leaf discs will give a blue-black colour when tested with iodine solution?

1. AW and X
2. BX only
3. CY and Z
4. DY only

As printed in the paper