[Campbell Biology P.851] Which of the following statements accurately describes the dynamic ... | Practice Question

Which of the following statements accurately describes the dynamic nature and regulation of plasmodesmata according to the provided text?

  • A: Plasmodesmata are unchanging pore-like structures, with their pore size fixed at approximately 2.5 nm for all molecules.
  • B: Their opening and closing can be rapidly influenced by factors such as turgor pressure, cytosolic Ca2+ level, and cytosolic pH.
  • C: They primarily involved in the apoplastic transport of water and solutes, rather than symplastic communication.
  • D: Plant cells do not actively regulate plasmodesmata; only viral movement proteins can alter their state.

Explanation

The section 'Changes in Plasmodesmatal Number and Pore Size' explicitly states: 'Recent studies, however, have revealed that plasmodesmata are highly dynamic. They can open or close rapidly in response to changes in turgor pressure, cytosolic Ca2+ level, or cytosolic pH.' This directly supports option B.