Nettle leaves are covered in stiff hairs. Each hair breaks when it is touched and injects a substance that stings. Which two types of defence does a nettle hair combine?
A physical barrier and an antibacterial chemical
A mechanical adaptation and a chemical defence
A physical barrier and a mechanical adaptation
A mechanical adaptation and an antibacterial chemical
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.