[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]​

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

every el niño cycle is different. every year.

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.