A selective weed killer containing auxin kills the broad-leaved weeds in a lawn but leaves the narrow-leaved grass unharmed. Which statement explains how it does this?
It is absorbed by the roots of broad-leaved plants but not by their leaves
It is absorbed by the roots of narrow-leaved plants but not by their leaves
It disrupts the normal growth patterns of broad-leaved plants only
It disrupts the normal growth patterns of narrow-leaved plants only
39 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.