[Campbell Biology P.840] Based on Figure 36.7 a , a flaccid plant cell is placed in a 0.4 M ... | Practice Question

Based on Figure 36.7 a , a flaccid plant cell is placed in a 0.4 M sucrose solution. Which of the following statements accurately describes the water movement and the cell's final state?

  • A: Water will move from the sucrose solution into the cell until the cell becomes turgid.
  • B: The initial cellular water potential (-0.7 MPa) is lower than the environmental water potential (-0.9 MPa), causing water to exit the cell.
  • C: Water will move out of the cell, causing it to plasmolyze, and at equilibrium, both the cell and the solution will have a water potential of -0.9 MPa.
  • D: The pressure potential of the cell increases from 0 to 0.7 MPa as water leaves the cell.

Explanation

Figure 36.7 a shows that the initial cellular water potential Ψ = -0.7 MPa is higher than the environmental water potential Ψ = -0.9 MPa . Water moves from a region of higher water potential to a region of lower water potential. Therefore, water will move out of the cell, causing it to lose turgor and plasmolyze. At osmotic equilibrium, the water potentials of the cell and its surroundings will be equal, which is -0.9 MPa.