Water moving through the xylem vessels in a tall maize plant exerts pressure on the walls of the vessels.
Which feature helps the xylem vessels withstand this pressure?
Sieve plates across the end walls support each vessel.
A large permanent vacuole keeps each vessel cell firm.
Companion cells supply energy to the vessel cells.
Lignin is laid down in spirals in the vessel walls.
282 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.