Transpiration Transpiration LabLabYour final long lab report!Your final long lab report!

Transpiration is…Transpiration is…

The process by which plants lose water The process by which plants lose water through stomata of leaves. As a result…through stomata of leaves. As a result…

Water moves up through plant stems in Water moves up through plant stems in xylem due to the special properties of xylem due to the special properties of waterwater

CohesionCohesion

AdhesionAdhesion

How do stomata control How do stomata control this important task?this important task?

It’s really up to the guard cells!It’s really up to the guard cells!

When water is plentifulWhen water is plentiful

Guard cells are turgid, and stomata are Guard cells are turgid, and stomata are openopen

When plants are stressed When plants are stressed due to insufficient ground due to insufficient ground water…water…

Plants close stomata Plants close stomata during certain conditionsduring certain conditions

Bright sunny daysBright sunny daysWindy daysWindy days

What do stomata do What do stomata do when the humidity is when the humidity is high?high?

Great Question! Let’s conduct an Great Question! Let’s conduct an experiment and see…experiment and see…

We are going to use a plant We are going to use a plant that is commonly planted in that is commonly planted in our area…our area…

Impatiens sp.Impatiens sp.

Impatiens spImpatiens sp. Are…. Are…

Water loving plants that need Water loving plants that need water everyday in our hot NC water everyday in our hot NC summerssummers

A great experimental plant to A great experimental plant to test transpiration because of test transpiration because of their high water consumptiontheir high water consumption

You will need to write You will need to write your own procedure for your own procedure for this lab, but in general, this lab, but in general, here is what we will be here is what we will be doing:doing:

We will simulate 3 possible We will simulate 3 possible environmental conditions:environmental conditions:

1.1. A sunny day (using a bright A sunny day (using a bright light)light)

2. A windy day (using a fan)2. A windy day (using a fan)

3. A humid day (using a terrarium 3. A humid day (using a terrarium with a bowl of water)with a bowl of water)

What have we forgotten?What have we forgotten?

The control! The control!

Our control will be room Our control will be room conditions with no variable conditions with no variable appliedapplied

Include 2 graphs in your Include 2 graphs in your analysisanalysis

1.1. Make a line graph of the % change in Make a line graph of the % change in mass from Monday to Friday for the mass from Monday to Friday for the control and the 3 experimental control and the 3 experimental variables. Also include the class variables. Also include the class average data.average data.

2.2. Make a bar graph for the overall % Make a bar graph for the overall % change in mass for the control and the change in mass for the control and the 3 experimental variables. Include both 3 experimental variables. Include both your data and the class average data.your data and the class average data.

What about the What about the hypothesis?hypothesis?

Write your hypothesis (on your data Write your hypothesis (on your data sheet) with your lab partner before you sheet) with your lab partner before you start the experiment. Remember to relate start the experiment. Remember to relate the experimental variables to the control.the experimental variables to the control.

1.1. Get 4Get 4 Impatiens Impatiens plants—1 control plant plants—1 control plant and 3 for the experimental variables. You and 3 for the experimental variables. You may need to cut the packs apartmay need to cut the packs apart

2.2. Water your 4 plants. Water your 4 plants.

3. Pinch off all flowers or flower buds, 3. Pinch off all flowers or flower buds, because they have mass, and mass is because they have mass, and mass is our dependent variable.our dependent variable.

4. Put a baggie around the root system 4. Put a baggie around the root system (keep the plant in the plastic pot) and (keep the plant in the plastic pot) and close with a twist tie.close with a twist tie.

5. Label each plant with your name and 5. Label each plant with your name and experimental variable.experimental variable.

6. Find the mass of each plant and record 6. Find the mass of each plant and record on your data table.on your data table.

7. Place each plant in the appropriate 7. Place each plant in the appropriate environment. environment.

8. Find the mass of each plant, Tuesday-8. Find the mass of each plant, Tuesday-Friday. On Friday we will compile class Friday. On Friday we will compile class data for your lab report.data for your lab report.

9. Write your lab report which will be due 9. Write your lab report which will be due Friday, May 1.Friday, May 1.