Name Date Period s7

Name Date Period WEB Lab: Transpiration Directions: 1. Go to http://www.phschool.com/science/biology_place/labbench/lab9/intro.html 2. Record summaries/key concepts/drawings etc. for each link you complete.

Introduction 1. What will you be doing in this lab?

2. What is transpiration?

Key Concepts 1: 1. Describe the movement of water up xylem vessels.

2. Click on “closer look.” Describe what you see.

Concept 1: Hydrogen Bonding: Draw the picture and describe what you see.

Concept 2: The Process of Transpiration: What is the function of the stomata?

Test Yourself: 1. What property of water accounts for the fact that molecules of water "grab" the walls of the thin xylem vessels?

2. Water molecules pull each other like beads on a string; as one molecule is evaporated through a stoma, another is pulled up. What property of water is demonstrated here?

3. Place the following in order (list the letters), from highest water potential to lowest water potential, under normal conditions. a. Mesophyll of leaves b. Outside air around leaf c. Spaces around roots d. Inside the xylem vessels Concept 3: 1. How do guard cells function?

2. What is the difference between a flaccid guard cell and a turgid guard cell?

Concept 4: Guard cell function animation Describe what happens when guard cells open and close.

Concept 5: Transpiration and Photosynthesis Write the equation for photosynthesis below. Concept 6: Factors that affect the rate of Photosynthesis 1. Which condition would result in the higher rate of transpiration: light or dark?

2. Which condition would result in the higher rate of transpiration:humid environment or dry environment?

3. Which condition would result in the higher rate of transpiration: breezy conditions or still air?

4. Which condition would result in the higher rate of transpiration:hot environment or warm environment?

Design of the Experiment 1. What is a potometer?

2. Label the figure to the right. Describe the basic elements.

Experiment 1: An Overview 1. What are the four different environments to be tested?

2. What is the control? 3. Why should you measure water loss? Experiment 2: How to Calculate Leaf Surface Area What is the surface area of this leaf in cm2? Follow directions! Analysis of Results I *YOU NEED A CALCULATOR FOR THIS!

Condition Total Water Leaf Leaf Surface Water Loss in Loss after 30 Surface Area in m2 ml/m2/30 min min Area in cm2 Room (control) 10/10,000= 0.004 ml 10

Bright light 0.006 ml 12

Fan (wind) 0.008 ml 10

Mist 0.002 ml 12

Lab Quiz I (Record your answers below)

1. 5. 2. 6. 3. 7. 4. 8. #CORRECT: ____/8 total Key Concepts 2: Label: Analysis of Results II

DIAGRAM NAME OF TISSUE FUNCTION A B C D

Lab Quiz II (Record your answers below) 1. 2. 3. 4. #CORRECT: ____/4 total Conclusion : One paragraph describing what you learned using complete sentences. Yay! You are done with your weblab!