1. Investigation of Leaf Stomata
Lab Experiment for Section 5.2

2. Please remember…
stoma = singular.
stomata = plural.

3.  Pre-Lab Questions:
1.) What is the primary structure of stomata? Please draw and label a picture. Where are stomata located on a plant leaf?
Stomata (small openings) are typically scattered about the lower epidermis (underside of leaf). Each stomata is surrounded by a pair of guard cells

4. Your drawing should be based on this image.

5.  Pre-Lab Questions:

6.  Pre-Lab Questions:

7. 2.) What is the primary function of stomata?
 Pre-Lab Questions:
2.) What is the primary function of stomata?
Stomata allow for the plant to “breath”.

8.  Pre-Lab Questions:
3.) What enters the leaf through the stomata? What exits the leaf through the stomata?
Through these holes…
1. carbon dioxide enters the leaf.
2. water is released (transpiration).
3. oxygen is released.

9.  Pre-Lab Questions:
4.) What happens to the stomata when guard cells swell? What happens to the stomata when guard cells shrink?
When guard cells swell, the stomata open. When the guard cells shrink, the stomata close.  Plants respond to changes in temperature & humidity by opening or closing their stomata.

10.  Pre-Lab Questions:

11. Post Lab Questions:
1. Will plants have more stomata open during the day than during the night? Explain.
Generally, stomata work on a regular day and night cycle where each stoma opens during the day and closes again at night. (Exceptions to this rule occur in desert plants.)

12. Post Lab Questions:
2. Develop a hypothesis about the number of open stomata found in a plant kept in the dark compared to a plant in the light. Write your hypothesis below, and make sure that it is a complete sentence. (You should form 2 hypotheses.)
If a plant is kept in the dark, then the number of open stomata found on the plant leaves will decrease.
If a plant is kept in the light, then the number of open stomata found on the plant leaves will increase.

13. Post Lab Questions:
3. Answer the following questions by referring to the image provided.

14. Post Lab Questions:
Write the number & name of the structure(s) that regulate the opening & closing of the stomata.
8 - guard cells
Which number indicates where oxygen exits the leaf?
9 - stomata, same place where water exits and carbon dioxide enters