Which adaptation of xylem vessels prevents the tubes from collapsing inward under the tension of the transpiration stream?
Thickened walls containing lignin
Small holes (pits) in the vessel walls
The absence of cytoplasm and nuclei
The complete breakdown of end walls between cells
82 exam-style questions on OCR GCSE Biology 2.1 Supplying the cell, covering 2.1.1 Transport across cell membranes, 2.1.2 Mitosis and the cell cycle, 2.1.3 Importance of cell differentiation, and 2.1.4 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.