Introduction
Through this experiment, we will see the stomata of a leaf.
Basic Building Concept
1. The pores which are present on the surface of the lower and upper side of the leaves are called stomata. These can not be seen with naked eyes.
2. This can only be seen through a compound microscope.
Aim
To prepare a temporary mount of a leaf peel to find the stomata of a leaf.
Materials Required
1. Leaf of Tradescantia/periwinkle/balsam,
2. Slide,
3. Coverslip,
4. Forceps,
5. Needles,
6. Cotton cloth,
7. Brush,
8. Blotting paper,
9. Watch glass,
10. Blade,
11. Dropper,
12. Glycerine,
13. Safranin,
14. Compound microscope.
Theory
1. The pores which are present on the lower and upper epidermis of the leaves are called stomata. They are higher in numbers on the lower side of the leaves.
2. Two kidney-shaped guard cells surround one stoma.
3. Each cell has many chloroplasts and a nucleus.
4. Each cell is surrounded by a differentially thick wall and is elastic.
5. The work of stomata is to exchange water vapour, carbon dioxide, and oxygen from plants and the atmosphere.
6. Change in turbidity of cells helps in opening and closing of pores.
Procedure
Step 1: Take a fresh leaf and remove peels from its lower surface.
Step 2: Put this leaf in a glass full of water.
Step 3: Add two to three drops of safranin to the glass to avoid staining the leaf.
Step 4: Put this leaf in the centre of the slide with the help of a brush.
Step 5: Over the slide, put a drop of glycerin.
Step 6: Now, place a coverslip over the peel.
Step 7: With the help of blotting paper, remove the excess water.
Step 8: Observe this slide under the compound microscope. First under lower magnification and then under higher magnification.
Observations
1. We have observed that the leaf peel consists of a number of cells. These cells have irregular boundaries, and no intracellular space is present between them.
2. Cells are present in a single layer.
3. In those epidermis cells, pores can be seen easily.
4. Two guard cells are present between each pore.
5. Every cell has several chloroplasts and a nucleus.
Result
From the mount of the leaf, we have seen its small pores, and these pores are called stomata. Stomata are enclosed by two seeds. Each seed has a nucleus and several chloroplasts.
Precautions
1. The Leaves should be fresh.
2. Clean the slide before use.
3. Don’t let the leaf get dry.
4. Use blotting to remove extra glycerine.
VIiva Questions with Answers
Q.1 What was the aim of our experiment?
ANS. To prepare a temporary mount of a leaf peel to find the stomata of a leaf.
Q.2 What do you understand about stomata?
ANS. The pores which are present on the surface of the lower and upper side of the leaves are called stomata. These can not be seen with naked eyes.
Q.3 Why did you use glycerine in the experiment?
ANS. To avoid the leaf from drying.
Q.4 What do you understand about guard cells?
ANS. Guard cells are kidney-shaped cells that surround the stomata.
Q.5 Name the shape of the dicot guard cell.
ANS. Kidney shape.
Q6 Name the shape of a monocot guard cell.
ANS. Dumb-bell-shape
Q.7 What is the instrument called which measures the relative size of stomata?
ANS. Porometer
Q.7 How many nuclei can be present in a guard cell?
ANS. One
Q.8 What is the function of stomata?
ANS. To transfer water vapour, oxygen, and carbon dioxide between plants and the atmosphere.
Q.9 What do you know about transpiration?
ANS. Transpiration is the process by which water gets vaporises from the surface of leaves.
Q.10 Opening and closing of stomata are done by which change?
ANS. Change in turbidity of guard cell.
Saquib Siddiqui is a Mechanical Engineer and a content creator. He has special interest in science experiments and teaches the same to school and college students. He is also a technical lead at RUDE LABS PVT. LTD.
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