A plant has mature leaves on the lower part of its stem and a growing, leafless shoot tip above them. The plant is kept in bright light. A short section of phloem between the mature leaves and the shoot tip is destroyed, but the xylem remains undamaged.
Which change is most likely in the shoot tip after the phloem is damaged?
More dissolved sugar reaches the shoot tip because it is carried upwards through the undamaged xylem
Dissolved sugar builds up in the shoot tip because the damaged phloem prevents movement towards the leaves
The amount of dissolved sugar stays the same because it is made in the leafless shoot tip
Less dissolved sugar reaches the shoot tip because transport from the mature leaves is interrupted
74 exam-style questions on AQA GCSE Biology 2.3 Plant tissues, organs and systems, covering 2.3.1 Plant tissues and 2.3.2 Plant organ system. Each one has a worked solution and a mark scheme showing where the marks go.