Stomata Lab Procedures:
1. Obtain one leaf.
2. Paint a streak (at least one square centimeter) of clear nail polish on the
underside of the leaf surface being studied.
3. Allow the nail polish to dry completely. About 2-5 minutes
4. Tape a piece of clear cellophane tape to the dried nail polish patch.
5. Gently peel the nail polish patch from the leaf by pulling on a corner of the
tape and "peel" the fingernail polish off the leaf. This is the leaf impression
you will examine.
6. Tape your peeled impression to a very clean microscope slide.
7. Examine the leaf impression under a light microscope.
8. Search for areas where there are numerous stomata, and where there are
no dirt, thumb prints, damaged areas, or large leaf veins. On your lab paper,
draw the leaf surface with stomata and label if the stomata is open or
closed. Answer the lab questions.
9. Make sure to also include the magnification when you draw your picture.
Stomata Lab Procedures:
1. Obtain one leaf.
2. Paint a streak (at least one square centimeter) of clear nail polish on the
underside of the leaf surface being studied.
3. Allow the nail polish to dry completely. About 2-5 minutes
4. Tape a piece of clear cellophane tape to the dried nail polish patch.
5. Gently peel the nail polish patch from the leaf by pulling on a corner of the
tape and "peel" the fingernail polish off the leaf. This is the leaf impression
you will examine.
6. Tape your peeled impression to a very clean microscope slide.
7. Examine the leaf impression under a light microscope.
8. Search for areas where there are numerous stomata, and where there are
no dirt, thumb prints, damaged areas, or large leaf veins. On your lab paper,
draw the leaf surface with stomata and label if the stomata is open or
closed. Answer the lab questions.
9. Make sure to also include the magnification when you draw your picture.
Name: _______________________ Date: _______________ Period: ____
STOMATA LAB
Read the background information before beginning the lab.
Use this to answer the pre-lab questions, lab data and
assist with the conclusion on the back.
Background:
During photosynthesis plants use carbon dioxide, water, and light to create sugars
for energy. Gas exchange
between plant tissues and
the atmosphere occurs in
the leaf of a plant, the
major organ of
photosynthesis, through
tiny pores called stomata
(plural). Besides being a pathway for the uptake of carbon dioxide, these stomata
are also a source of water loss through transpiration. Transpiration is when water
is leaves the plant through a stoma and turns into water vapor in the environment.
This creates a dilemma for many plants. How can plants maximize the uptake of
carbon dioxide and minimize water loss? What to do? Among other methods, it
turns out that plants are able to regulate the opening and closing of the stomata.
On each side of each stoma (singular) are two guard cells. When both guard cells
swell with water, a gap opens between them, and the stoma is OPEN. When the
water is removed from the guard cells, the cells shrink, the edges of the guard cells
come into contact, and the stoma is CLOSED. In this way, the plant can regulate
the uptake of carbon dioxide and the loss of water. The following diagram shows a
closed stoma on the left and an open stoma on the right.
Name: ____________________________ Date: _____________ Period: _____
Stomata Lab
Introduction
1. What is transpiration?
2. What are the pores on the leaves called that open and close to allow water and gas to
enter and exit the leaf?
3. What are the names of the two cells that surround the stoma?
Results
_______________X
Conclusion
1. When transpiration is occurring at too fast of a rate, what do the guard cells do?
2. Where on a leaf (top or bottom) are more stoma found? ______________ Why?
3. ___________ _____________ gas moves into the stomata because it is a
____________ of photosynthesis. _______________ gas moves out of the stomata
because it is a _________________ of photosynthesis.
4. What role does the stoma play in transpiration.
5. Why might a cactus have fewer stomata than a plant found in a tropical region?.
6. If you were looking at leaves of an aquatic plant, where would most of the stomata
be on the leaves (top or bottom)? __________________ Why?