[Campbell Biology P.846] Figure 36.14a illustrates how guard cell shape changes to regulate ... | Practice Question

Figure 36.14a illustrates how guard cell shape changes to regulate stomatal opening. What structural feature of the guard cell wall is crucial for its outward bowing during turgor increase?

  • A: The uniform thickness of the cell walls.
  • B: The random arrangement of cellulose microfibrils.
  • C: The radial orientation of cellulose microfibrils in the cell walls.
  • D: The presence of a large central nucleus.

Explanation

Figure 36.14a and its accompanying text clearly state that 'The radial orientation of cellulose microfibrils in the cell walls causes the guard cells to increase more in length than width when turgor increases.' This radial arrangement is what facilitates the outward bowing and subsequent stomatal opening.