Why do plants growing outside often have shorter and thicker stems than plants of the same species grown indoors?

Question

A.  The plants inside have a more constant source of light and therefore a higher level of phytochrome.
B.  The outdoor plants are subject to mechanical stresses and they are exhibiting a thigmomorphogenic response.
C.  The outdoor plants are subject to touch by animals and other plants and are exhibiting a thigmotropic response.
D.  The indoor plants have elevated levels of auxin and are therefore taller than the outside plants.

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 growth of protected vs. exposed 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

B.  The outdoor plants are subject to mechanical stresses and they are exhibiting a thigmomorphogenic response.

Clarify Question
· What is the key concept addressed by the question?
        o This question is asking about the differences that occur in the structures of indoor vs. outdoor plants.
· What type of thinking is required?
        o This question is asking you to evaluate-the conditions around indoor and plants grown outside.
· What key words does the question contain and what do they mean?
        o Indoor, which in this context refers to plants that have relatively constant conditions in which to grow.
        o Outside, which in this context refers to plants that grow in conditions that are not modified by humans.

Gather Content
· What do you already know about growth of protected vs. exposed plants? How does it relate to the question?
        o Plants grown inside are typically grown in light, moisture, and other conditions that are as near optimal as humans can manage.
        o Plants grown outside are subject to the extremes of the weather and environment.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o Stem thickness is not regulated by auxin.
        o Phytochrome does not play a role in stem thickness.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Stem thickness is something that can be the result of thigmomorphogenesis.
        o Plants grown outside would be subject to the force of the wind, which would result in the thickening of the stem via thigmomorphogenesis to withstand the force of the wind.

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?
· Evaluate level:
This question asked you to evaluate the differences between plants that grow indoors vs plants that grow outside.  Answering this question correctly depended on your ability to evaluate plant responses in the different environments. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that indoor plants do not face the environmental pressures that plants grown outside do? Did you have trouble weighing the merits of indoor vs outside conditions to determine the correct answer?