Prepare a temporary mount of any leaf peel observe the stomata and draw their picture? write a short note on the same 9th books answers
Answers
Material Required ;
- A potted plant of Bryophyllum or Tradescantia
- Needles
- Forceps
- Watch glass
- Dropper
- Glass slides
- A brush
- Coverslips
- Blotting paper
- Safranin
- Compound microscope
- Glycerine
Procedure ;
1. Pick a healthy leaf from the potted plant.
2. 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.
3. In the watch glass, stain the sample by adding some drops of safranin through a dropper.
4. Take the peel out after 2-3 minutes. Set it on a clear glass slide.
5. Add a drop of glycerin on the peel. Put a clear coverslip over it gently using a needle.
6. Excess glycerin and stain can be removed using blotting paper.
7. Examine the slide first under a low-power and then under a high-power magnification of a compound microscope.
Observation ;
1. Visible epidermal cells. The cells in their outline are irregular with no intercellular spaces.
2. Small openings, stomata are scattered through the epidermal cells.
3. Guard cells are observed which have chloroplasts and nucleus.
4.Guard cells are observed having a thin outer covering and a thick inner boundary(concave).
5.Guard cells control the closing and opening of the stomata.
Conclusion ;
Epidermal cells are found containing stomata on the lower surfaces of the leaf.
[ Also ]
Precautions ;
1. Avoid folding the leaf too much. The peel should be snipped to a proper size.
2. The peel should always be placed at the centre of the slide and the slides should be held from the sides.
3. The peel should neither be overstrained nor under strained.
4. A brush should be used to handle the peel, otherwise would damage cells.
5. Glycerin should be used in order to prevent drying of the peel.
6. Coverslip needs to be placed in such a way that air bubbles are avoided.
7. Blotting paper can be used to remove excess stain.