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Has anyone ever seen/done this lab before??   :thi:


Lab 3 Worksheet:  Plant Transpiration

Student instructions:  Follow the step-by-step instructions for this exercise found on the worksheet below and in the virtual lab and record your answers in the spaces below.  Submit this completed document by the assignment due date found in the Syllabus.

Please make sure that your answers are typed in RED.

Please type your Name and Student ID Number here:


Directions

1.   Open the Virtual Lab titled “Plant Transpiration.”
2.   Read the background information found under the “Question” area first, and then read the procedure information posted there as well. 

3.   Click on the “Information” button in the laboratory area and read through the information presented.

4.   If you come upon terms that are unfamiliar to you, please refer to your textbook for further explanation or search the word here:  http://encarta.msn.com/encnet/features/dictionary/dictionaryhome.aspx (http://encarta.msn.com/encnet/features/dictionary/dictionaryhome.aspx)

5.   At this point, you are ready to begin the lab exercise.  Click on one of the plant specimens and drag it to the potometer as directed in order to begin the activity. 

6.    Complete the exercise as directed, recording any data or information collected in Table I below.  Record all data in Table 1 to the 1st (tenths) decimal place.

7.   When you are finished, please answer all of the Lab Questions below.


Procedure

1.    Again, please make sure you have read through all of the information in the “Question” and “Information” areas. 

2.    In this exercise, you will test the effects of various environmental conditions on the rate of plant transpiration.  To begin, click on one of the plant specimens   and drag it to the potometer;   the name of the plant will then appear. 

3.    Click on the clock icon to begin the experiment.

4.    After the simulated hour has passed, you will be shown the temperature   
at which the experiment took place and the volume   of fluid transpired by the plant (in mL).  Place all of this information in Table I below. 

5.    Now that you have assessed the transpiration rate of this plant under normal conditions, click and drag one of the three appliances to the laboratory bench next to the potometer.   .

6.    Click the clock to begin the second experiment. After collecting your data as above, repeat these procedures on your plant specimen using the remaining two appliances.

7.    When you are completely finished testing your specimen under all four conditions, click on a new plant specimen and drag it to the potometer.  Following all of the procedures above, collect your data on the transpiration rates of this plant and place them in Table I below.  When you have completely analyzed all four visible plant specimens, you can click the “Reset” button to obtain new plant specimens.  There are 9 total plants in all that need to be tested under all four environmental conditions.

8.    Answer Lab Questions 1-18 below.

Table I:  Total Amount of Water (mL) Transpired in One Hour
Plant Type   Normal Conditions (@21oC)   With Heater(@27oC)   With Fan (@21oC)   With Lamp (@21oC)
Arrowhead            
Coleus            
Devil’s Ivy            
Dieffenbachia            
English Ivy            
Geranium            
Rubber Plant            
Weeping Plant            
Zebra Plant            

Lab Questions:

1.    Transpiration in plants is driven by which of the following?
a.   Gravity
b.   Capillary action
c.   Static electricity
d.   All of the above

2.   Which of the following statements about stomata is true?
a.   They are found on plant roots.
b.   They permit the intake of carbon dioxide.
c.    They permit the intake of oxygen.
d.    All of the above.

3.   Water can be lost by a plant through which process(es)?
a.   Evaporation
b.   Transpiration
c.   Condensation
d.   A and B

4.    Which environmental condition in your experiments served as the control?
a.   Heat
b.   Wind
c.   Light
d.   None of the above

5.   In your experiments, transpiration was observed by which of the following?
a.   Directly measuring the amount of water leaving the leaves through transpiration.
b.   Directly measuring the amount of water leaving the leaves through evaporation.
c.   Directly measuring the amount of water absorbed through the plant sprig’s stem.
d.   All of the above.

6.    Which environmental condition(s) always led to an increase in transpiration rate in each plant tested?
a.   Heat
b.   Wind
c.   Light
d.   A and B
e.   All of the above

7.    Wind did not have the greatest effect on transpiration rate in which plant type?
a.   Arrowhead
b.   Geranium
c.   Rubber Plant
d.   Weeping Plant
e.   None of the above

8.    Colder temperatures cause stomata to remain closed. Based on this information, if a plant were grown below 21oC, what would you expect transpiration rates to do?
a.    Increase
b.   Decrease
c.   Remain the same

9.    Wind appeared to increase the rate of transpiration in most plants tested.  This is most likely due to which fact?
a.   Humidity was increased
b.   Evaporation was increased
c.   Stomata were forced to close
d.   All of the above

10.    Cacti grow in arid regions such as deserts. Compared to other plants, b  transpiration in cacti would most likely be which of the following?
a.    Lower
b.   Higher
c.   The same

11.   Describe the process of transpiration in vascular plants.

12.   Describe any experimental controls used in the investigation.

13.   What environmental factors that you tested increased the rate of transpiration?

14.   Was the rate of transpiration increased for all plants tested?

15.   Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?

16.   Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?

17.   Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

18.   Of what value to a plant is the ability to lose water through transpiration?

1.    Transpiration in plants is driven by which of the following?
a.   Gravity
b.   Capillary action
c.   Static electricity
d.   All of the above

2.   Which of the following statements about stomata is true?
a.   They are found on plant roots.
b.   They permit the intake of carbon dioxide.
c.    They permit the intake of oxygen.
d.    All of the above.

3.   Water can be lost by a plant through which process(es)?
a.   Evaporation
b.   Transpiration
c.   Condensation
d.   A and B

4.    Which environmental condition in your experiments served as the control?
a.   Heat
b.   Wind
c.   Light
d.   None of the above

5.   In your experiments, transpiration was observed by which of the following?
a.   Directly measuring the amount of water leaving the leaves through transpiration.
b.   Directly measuring the amount of water leaving the leaves through evaporation.
c.   Directly measuring the amount of water absorbed through the plant sprig’s stem.
d.   All of the above.

6.    Which environmental condition(s) always led to an increase in transpiration rate in each plant tested?
a.   Heat
b.   Wind
c.   Light
d.   A and B
e.   All of the above

7.    Wind did not have the greatest effect on transpiration rate in which plant type?
a.   Arrowhead
b.   Geranium
c.   Rubber Plant
d.   Weeping Plant
e.   None of the above

8.    Colder temperatures cause stomata to remain closed. Based on this information, if a plant were grown below 21oC, what would you expect transpiration rates to do?
a.    Increase
b.   Decrease
c.   Remain the same

9.    Wind appeared to increase the rate of transpiration in most plants tested.  This is most likely due to which fact?
a.   Humidity was increased
b.   Evaporation was increased
c.   Stomata were forced to close
d.   All of the above

10.    Cacti grow in arid regions such as deserts. Compared to other plants, b  transpiration in cacti would most likely be which of the following?
a.    Lower
b.   Higher
c.   The same

Cacti reduce water loss through transpiration by crassulacean acid metabolism. Here, transpiration does not take place during the day at the same time as photosynthesis, but at night. ranspiration is the loss of water by evaporation through the leaves. Because of the lack of water in a desert region, it is necessary for a cactus to have a lower transpiration volume in order to survive. They accomplish this by lowering the volume of their leaves, which in many species are microscopic.

Thank you Howard! I greatly appreciate the help!  :)

can anyone explain me lab 3 Alters and Alters,  plant Transpiration

Question 5
in your experiments, transpiration was observed by which of the following

question 11
Describe any experimental controls used in the investigation.( I would like to know for this question if I have to describe it, base on heat; lapm and wing?) how which factor I should describe.

question 18

Hi!

q5: Directly measuring the amount of water leaving the leaves through transpiration

q11: Experimental group: Plant exposed to heat. Control group: Plant not exposed to heat.

That's really all you have to mention I think.

Thanx again Howard!  :-X

Could someone please help me with the question below. They are from the Alters 3 lab

11.   Describe the process of transpiration in vascular plants.
13.   What environmental factors that you tested increased the rate of transpiration?

14.   Was the rate of transpiration increased for all plants tested?

15.   Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?

16.   Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?

17.   Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

18.   Of what value to a plant is the ability to lose water through transpiration?

Transpiration is the evaporation of water from plants. It occurs chiefly at the leaves while their stomata are open for the passage of CO2 and O2 during photosynthesis.

But air that is not fully saturated with water vapor (100% relative humidity) will dry the surfaces of cells with which it comes in contact. So the photosynthesizing leaf loses substantial amount of water by evaporation. This transpired water must be replaced by the transport of more water from the soil to the leaves through the xylem of the roots and stem.

Environmental factors that affect the rate of transpiration

1. Light

Plants transpire more rapidly in the light than in the dark. This is largely because light stimulates the opening of the stomata (mechanism). Light also speeds up transpiration by warming the leaf.

2. Temperature

Plants transpire more rapidly at higher temperatures because water evaporates more rapidly as the temperature rises. At 30°C, a leaf may transpire three times as fast as it does at 20°C.

3. Humidity

The rate of diffusion of any substance increases as the difference in concentration of the substances in the two regions increases.When the surrounding air is dry, diffusion of water out of the leaf goes on more rapidly.

4. Wind

When there is no breeze, the air surrounding a leaf becomes increasingly humid thus reducing the rate of transpiration. When a breeze is present, the humid air is carried away and replaced by drier air.

5. Soil water

A plant cannot continue to transpire rapidly if its water loss is not made up by replacement from the soil. When absorption of water by the roots fails to keep up with the rate of transpiration, loss of turgor occurs, and the stomata close. This immediately reduces the rate of transpiration (as well as of photosynthesis). If the loss of turgor extends to the rest of the leaf and stem, the plant wilts.

The volume of water lost in transpiration can be very high. It has been estimated that over the growing season, one acre of corn (maize) plants may transpire 400,000 gallons (1.5 million liters) of water. As liquid water, this would cover the field with a lake 15 inches (38 cm) deep. An acre of forest probably does even better.