A sycamore seed germinates in loose soil on a river bank. Its young roots grow downwards through the soil.
Which statement explains the advantage of the direction taken by these roots?
The roots enter the soil, where they absorb water and mineral ions and anchor the seedling.
The roots absorb auxin from the soil, which speeds up cell elongation equally throughout each root.
The roots reach brighter conditions, allowing their cells to make more glucose by photosynthesis.
The roots grow away from gravity, ensuring the seedling develops upright whichever way the seed landed.
87 exam-style questions on AQA GCSE Biology 5.4 Plant hormones, covering 5.4.1 Control and coordination and 5.4.2 Use of plant hormones (HT only). Each one has a worked solution and a mark scheme showing where the marks go.