Learners prepared temporary mount of a lily leaf peel in order to show the stomata of a leaf.
Plants are the primary producers. They carry out physiological processes such as photosynthesis and respiration which requires a gas exchange between the tissues of plants and the atmosphere. This process is carried out through tiny openings located in leaves, known as stomata.
Stomata are small elliptical openings on leaves that contain chloroplasts. They are girdled by two-kidney shaped cells known as guard cells on either side of the stomata. The guard cells possess a thick inner wall and a thin outer covering which control the closing and opening of the pores of stomata.
Turgidity of the guard cells causes the stomata to open while the flaccid nature of the guard cells causes the stomata to close.
Learners used
- Plant leaf
- Needles
- Forceps
- Watch glass
- Dropper
- Glass slides
- A brush
- Coverslips
- Blotting paper
- Safranin
- Compound microscope
- Glycerine
- Learners Picked a healthy leaf from the potted plant
- Fold the leaf to gently pull the peel apart to separate a peeled section from the lower surface of the leaf. Use the forceps to perform this step. Allow the peel to remain in a watch glass holding water for some time.
- In the watch glass, stain the sample by adding some drops of safranin through a dropper.
- Take the peel out after 2-3 minutes. Set it on a clear glass slide
- Add a drop of glycerin on the peel. Put a clear coverslip over it gently using a needle.
- Excess glycerin and stain can be removed using blotting paper
- Examine the slide first under a low-power and then under a high-power magnification of a compound microscope.
Observation
- Visible epidermal cells. The cells in their outline are irregular with no intercellular spaces
- Small openings, stomata are scattered through the epidermal cells
- Guard cells are observed which have chloroplasts and nucleus
- Guard cells are observed having a thin outer covering and a thick inner boundary(concave)
- Guard cells control the closing and opening of the stomata.
