Name:_____________________________________________
Period:_________
Online Transpiration Lab Activity
Prelab: Read your textbook pages 779, 778-792 and answer the following questions
1. Why are some plants classified as “vascular?”
2. Describe the pathway water takes through a plant?
3. What property of water causes water to “grab” the walls of the thin xylem vessels?
4. What property of water allows each molecule to be pulled up like beads on a string as
transpiration occurs?
5. What structure allows necessary gases to enter and water to leave?
6. How is K+ important to the functioning of stomata?
7. Explain why the evaporation of water from leaves lowers their temperature.
8. How does water potential play a role in transpiration?
Transpiration Online Lab
Go to the website: http://www.mhhe.com/biosci/genbio/virtual_labs/BL_10/BL_10.html
(you can also Google: mhhe transpiration lab)
Lab Question:
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Name:_____________________________________________
Period:_________
Variables:
 IDV ‘s– _________________________________________________________________________________
 DV – ___________________________________________________________________________________
 Controlled – __________________________________________________________________________
Hypothesis: (If/then statement with specific biology knowledge from textbook to support
your statement)
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Data Table:
Amount of Water Transpired in 1 Hour (mL)
Normal
With Fan
With Heater
Arrowhead
Coleus
Devil’s Ivy
Dieffenbachia
English Ivy
Geranium
Rubber Plant
Weeping Fig
Zebra Plant
2
With Lamp
Name:_____________________________________________
Period:_________
Analysis: Make a bar graph for EACH condition tested.
Conclusion Questions:
1. Did any of the environmental factors (heat, light, or wind) increase the transpiration
rate more than the others? Why?
2. Which plant was best adapted to each condition, showing the least amount of change?
3. Which plant was least adapted to each condition?
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Name:_____________________________________________
Period:_________
4. Why do you think different species of plants transpire at different rates?
5. List 3 physical adaptations can plants have to resist transpiration changes in different
biomes.
6. Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's
rate of transpiration be affected?
Ecological Questions:
1. How do the Santa Ana winds affect the plant life in Southern California?
2. Why is it important to grow plants native to your area in terms of transpiration?
3. How would a humid environment effect transpiration rate and why?
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