| Aim | To prepare a temporary mount of a leaf peel and observe the stomata under a microscope. |
| Apparatus Required | Fresh leaves from a plant Glass microscope slides Scalpel or razor blade Forceps Dropper Distilled water Microscope A brush Blotting paper Safranin Glycerin |
| Theory | The primary producers in the ecosystem are plants, which engage in essential physiological processes like photosynthesis and respiration. These processes require a gas exchange between the plant tissues and the surrounding atmosphere, which occurs through small openings located on the leaves called stomata. The structure of stomata can be described as small, elliptical openings that contain chloroplasts and are surrounded by two-kidney shaped guard cells. These guard cells possess a thick inner wall and a thin outer covering, and they control the opening and closing of the stomata. The stomata open when the guard cells are turgid, and they close when the guard cells are flaccid. This process is crucial for regulating the gas exchange and water loss in plants. |
| Procedure | 1 .Select a healthy leaf from the potted plant. 2 .Using forceps, gently fold the leaf to separate a peeled section from the lower surface of the leaf. 3 .Place the peel in a watch glass filled with water, and let it soak for some time. 4 .Add a few drops of safranin stain to the watch glass containing the peel. 5 .After 2-3 minutes, remove the peel from the watch glass and place it on a clear glass slide. 6 .Add a drop of glycerin to the peel, and then gently place a clear coverslip over it using a needle. 7 .Use blotting paper to remove any excess glycerin and stain. 8 .Examine the slide under a low-power magnification of a compound microscope, and then switch to high-power magnification to observe the details. |
| Observation | The epidermal cells on the surface of a plant’s leaf have an irregular outline and lack intercellular spaces. Scattered throughout these cells are small openings called stomata. Within the stomata, there are specialized cells called guard cells that contain chloroplasts and a nucleus. The guard cells have a thin outer layer and a thick concave inner boundary, and they are responsible for regulating the opening and closing of the stomata. |
