To peel the epidermis layer from underneath of the plant leaf and count the average distance between the stomata.

Each part of the leaf needs an equal amount of carbon dioxide; otherwise the part with less carbon dioxide would die.

Prediction

The distance between the stomata should be equal because each part of the leaf needs an equal amount of carbon dioxide.

Equipment

• Microscope – to look at the peeled layer
• Leaf – to get the lower epidermis layer from it
• Nail Varnish – to make the lower epidermis layer stick to it
• Tweezers – to peel off the lower epidermis layer with them
• Slides and cover slips – to make the slide for the microscope
• Glycerol – to keep air bubbles out of the slides
• Pipette – to apply the glycerol to the slide
• Tissues – to wipe excess glycerol from slides
• Brush – to apply the nail varnish to the underside of the leaf. It should be available in the cap of the nail varnish

Method

1. Take the leaf, open the nail varnish bottle and apply the nail varnish with the brush to the underside of the leaf.
2. Wait 5-10 minutes.
3. Rip the leaf in two halves. There should be a transparent layer visible. If not, rip one of the halves again and again until a sufficiently big piece can be peeled off.
4. Use the tweezers to peel off the piece of epidermis. Peel slowly to make sure that the piece doesn’t rip accidentally.
5. Place the piece on the slide and use the pipette to apply the glycerol.
6. Use the tweezers to lower the cover slip onto the slide. Lower slowly to avoid bubbles.
7. Set up the microscope to high power. At high power one graticule unit is equal to 2.5µm.
8. Look at the slide through the microscope. Measure the distances between one stoma and 10 others, then move to a different field of view and repeat.
9. Put away the equipment.

Results

Mean = 3gu

Mean distance = 7.5 µm

Analysis

The distance between two stomata is on average 7.5 µm although I don’t see how I can say that because the distances were not regular, not even in the same range, one was 0.5gu and another was 7.4gu, sometimes they looked as if they overlapped.

Evaluation

The experiment went well, I can’t think of other experiments to investigate the same thing, and the equipment was fine. If I wanted to improve on this I would make more repeats.