Non-major General Biology students will examine Plants in Motion movies of a variety of plant responses to light and gravity. The students will answer questions based on introductory material and movies viewed.
Students will have completed a lab on photosynthesis and will have reviewed background information on plant structure (roots, stems, leaves).
Explain how plants respond in an adaptive way to light and gravity.
Some movies may be slow to load for students with a slow modem.
Text of Learning Exercise:
Plants use the process of photosynthesis to convert the energy of sunlight into chemical energy that the plant will use for growth and development. The perception of sunlight is necessary for plant development. The absence of light also elicits growth responses in plants. Examine the text and movies listed below and answer the questions.
Follow the navigation links and the instructions provided below. Questions answered will be submitted as part of Lab 6 on Photosynthesis.
Go to: http://sunflower.bio.indiana.edu/~rhangart/plantmotion/PlantsInMotion.html
Click on: Ticket to Enter Site
Read: Introductory Text NOTE: You will need QuickTime 5.0 to view movies If you don?t have it download it now.
Click on: Photomorphosis Read: Introductory Text
Click on: Sunflower dark and light Read: Text with each movie (NOTE: Movie may take a few minutes to load on some computers.)
Create a Table: Across the top of the table put light and dark. Down the side put:stem elongation; leaf (cotyledon) development,
chlorophyll production; hooked stems. As you read text fill-in the table indicating how light grown and dark-grown plants respond in each category listed.
Click on: Movie for Dark Grown Seedlings (right facing triangle) You may drag circular slider back to the beginning to view again. The triangles with lines next to them allow you to move forward or backward step-by-step through the movie.
Answer these questions. Q-1 How did the movies provide support for the table that you developed? Q-2 Which plant is most prepared to start photosynthesizing? Explain. Q-3 Prior to starting to photosynthesize, what was the energy source for the young plants? By what process did the plants get energy from this source? Q-4 The dark-grown plants had longer stems. What is a possible reason that the longer stems might be an advantage to the plants in the dark?
Click on: Dark-grown Arabidopsis Read: Text View: Movie
Q-5 Compare the Arabidopsis with the dark- grown sunflower movie.
Click on: Tropisms Read: Text
A positive tropism is when the plant grows toward the stimulus and a negative tropism is when the plant grows away from the stimulus.
Click on: Arabidopsis shoot phototropism Read: Text with both movies View: Blue-light induced phototropism movie View: Red-light enhanced phototropism movie
Q-6 Which plants responded most quickly to the blue light? Why? Q-7 Were the plants displaying a positive or negative phototropism?
Click on: Tomato Phototropism Read: Text View: Movie
Click on: Corn Phototropism Read: Text View: Movie
Click on: Cool Corn Plants Read: Text View: Movie
Click on: Sunflower phototropism Read: Text View: Movie
Click on: Arabidopsis shoot Gravitropism Read: Text View: Movie
Click on: Coleus Sh
oot Gravitropism Read: Text View: Movie
Click on: Sunflower Gravitropism Read: Text View: Movie
Q-8 Summarize your observations of plant stems response to gravity. Q-9 What is the adaptive value of plants responding in this way?
Click on: Corn root gravitropism Read: Text View: Movie
Q-10 Make a statement regarding the adaptive value of plant roots displaying a positive gravitropic response.