Some passion flower plants have small yellow structures on their leaves that look like butterfly eggs. A female butterfly will not lay her eggs on a leaf that already has eggs on it. The caterpillars that hatch from these eggs eat passion flower leaves. Which best explains how the yellow structures defend the plant?
The yellow structures contain a poison that kills the butterflies
The yellow structures act as a barrier that stops pathogens entering
The butterflies become trapped by the yellow structures and then die
Fewer caterpillars hatch on the plant, so less of the leaf is eaten
58 exam-style questions on AQA GCSE Biology 3.3 Plant disease, covering 3.3.1 Detection and identification of plant diseases and 3.3.2 Plant defence responses. Each one has a worked solution and a mark scheme showing where the marks go.