When plants are grown in hydroponic culture, their roots are suspended in an aerated solution. Why is the solution aerated? Check all that apply.

Question

_____  Both the light-dependent and the light-independent reactions of photosynthesis require oxygen.
_____  Oxygen is necessary for the root cells to produce ATP.
_____  Without oxygen, membrane transport in the roots would be impaired.
_____  A lack of oxygen would cause the water potential within the roots to decrease.
_____  Without oxygen, the xylem would stop flowing.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you already know about theimportance of oxygen in plants at the molecular in plants? How does it relate to the question?

Consider Possibilities
· What other information is related to the question? Which information is most useful?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

_____  Both the light-dependent and the light-independent reactions of photosynthesis require oxygen.
__X__  Oxygen is necessary for the root cells to produce ATP.
__X__  Without oxygen, membrane transport in the roots would be impaired.
_____  A lack of oxygen would cause the water potential within the roots to decrease.
__X__  Without oxygen, the xylem would stop flowing.


Clarify Question
· What is the key concept addressed by the question?
        o This question is asking about the importance of oxygen at a molecular level in plants.
· What type of thinking is required?
        o You are being asked to take what you already know and apply it to an unknown situation involving the needs of plants grown using hydroponic methodology.
· What key words does the question contain and what do they mean?
        o Hydroponic, which is a method of growing plants in water instead of soil.
        o Aerated, which means supplied with air.

Gather Content
· What do you already know about theimportance of oxygen in plants at the molecular in plants? How does it relate to the question?
        o The cells of living things use oxygen to make ATP.
        o In plant roots, ATP is used to actively transport ions into the root.
        o Movement of ions into the root lowers the water potential of the root.
        o When water potential is lowered, water flows into the root where it can be carried further into the plant.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o Oxygen is not required for photosynthesis.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
       o To answer this question, you must recognize the importance of ATP in ion transport and subsequently of water flow into and through the plant. Without oxygen, ATP would not be synthesized and this transport would cease.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

· Apply level:
       o This question asked you to understand the importance of oxygen in the physiology of plants. Answering this question correctly depended on your ability to use the importance of oxygen to plants in a new situation¼ If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that oxygen is necessary for ATP synthesis, or that ATP synthesis is necessary to drive ions and water into plants? Did you have trouble extending the need for oxygen and ATP to determine the correct answer?