Download Read the introdction and answer the following questions

Date ______
Tropism Web Activity
Name _________________
Hormones and Tropisms
Go to the website:
http://www.springer.com/cda/content/document/cda_downloaddocument/3701s.swf?SGWID=0-0-45-754500-0
Read the introduction and Click on the animation tab. Choose the “Photoropism Experimnets” option
1. After reading the introduction, why have plants evolved phototropism and gravitropism?
2. Watch the animations and describe the pattern of plant growth with each of the 4 different types
of blindfolds.
a. Clear cap:
b. Opaque cap:
c. Clear Sheath:
d. Opaque Sheath:
3. Click on the “Summary” button. What is the light sensitive part of the plant? Provide evidence to
support your answer.
Click on the animations tab. Select the “Gravitropism and Phototropism” option then select “Step
Through” at the bottom of the page. Watch the animation for both “Auxin in Gravitropism” and
“Auxin in Phototropism”
4. What hormone is responsible for tropisms in plants?
5. Where in the plant is the auxin originally located?
6. What effect does auxin have on plant cells?
7. In your own words explain how auxin causes gravitropism
when a plant is tipped on its side?
8. In your own words explain how auxin causes phototropism when light is shined on one side of a
plant?
Date ______
Tropism Web Activity
Name _________________
Plant Tropisms - Use this link to watch movies for the following tropisms.
http://www.pbslearningmedia.org/asset/lsps07_int_plantmovies/
Introduction
9. Explain why plant movements often go unnoticed?
Video 1: Seed Germination and Gravity
10. What is the difference between the two seeds in the video?
11. What is the first structure that emerges from the embryo (root or stem)?
12. After watching the video explain why is gravitropism important for seed germination?
Video 2: Light and Dark Responses
13. Explain how plants grow differently in the dark compared to the plants grown in the light?
14. Explain why seedlings would grow differently in the dark.
Video 3: Twining Vines
15. Why does this plant swing around as it grows?
16. What type of tropism is shown in the video?
17. Describe what happens when the plant finally bumps into the support?
Video 4: Plant Growth and Gravity
18. Describe what happens when the plant is turned on its side?
19. Does this video show a positive or negative response to gravity?