Meristematic stem cells in the vascular cambium are responsible for producing the specialized cells of the vascular transport system in plants, including xylem vessel elements and phloem sieve tube elements.
Which statement about these stem cells and the specialized cells they produce is correct?
Vascular cambium stem cells are pluripotent and can differentiate into any plant cell type, including palisade mesophyll and epidermal root hair cells.
Mature xylem vessel elements lack a living protoplasm and end walls, forming a continuous lignified tube that facilitates the low-resistance transport of water under tension.
Guard cells have cell walls of uniform thickness, allowing them to expand symmetrically to close the stomatal pore when they become turgid.
Sieve tube elements retain their nucleus and a high density of mitochondria to provide the ATP and proteins needed to actively load sucrose.
40 exam-style questions on OCR A A Level Biology Cell division, cell diversity and cellular organisation. Each one has a worked solution and a mark scheme showing where the marks go.