[10] 1.2
Study the graph below and answer the questions that follow.
Changes in the water potential of guard cells
and the lower epidermal cells
lower epidermal cells
-1000
-1100
Water potential (kPa)
-1200
guard cells
- 1 300
-1 400
Х
Y
Time
1.2.1
1.2.2
1.2.3
State the main difference between the graphs for the lower epidermal cells and for
the guard cells.
(2)
What is the water potential of the guard cells at time X?
Will the stomata of the plant be open or closed at time Y?
Explain your answer.
(3)
[7]​