a practical related to a experimexnt on onion peel
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Answered by
1
Objective:
To prepare a stained temporary mount of an onion peel and to record observations and draw labeled diagrams.
Apparatus and materials required:
An onion, glass slide, watch glass, coverslip, forceps, needles, brush, blade, filter paper, safranin, glycerine, dropper, water, and a compound microscope.
Theory:
All living organisms are made up of cells. The shape, size and the number of these units vary in organisms. The three major components of a cell are the cell membrane, cytoplasm and nucleus. In a plant cell, a cell wall surrounds the cell membrane.
Procedure:
1. Take an onion and remove its outermost peel.
2. Now cut a small part from an inner scale leaf with the help of a blade.
3. Separate a thin, transparent peel from the convex surface of the scale leaf with the help of forceps.
4. Keep this peel in a watch glass containing water?
5. Add two drops of safranin stain in the watch glass to stain the peel.
6. Take a clean slide and put a drop of glycerine in the centre of the slide.
7. With the help of a brush and needle transfer the peel on the slide. Glycerine prevents the peel from drying up.
8. Carefully cover it with a coverslip and avoid any air bubble from entering interring the coverslip.
9. Remove any excessive glycerine with a filter paper.
10. Observe the prepared mount of the peel under the low and high magnification of a compound microscope.
Observations:
A large number of rectangular cells are visible. These cells lie close to each other with intercellular spaces between them. These cells are surrounded by distinct cell walls. These cells have a dark stained nucleus and a large vacuole in the centre.
Precautions:
1. Overstaining and understaining should be avoid
2. Folding of the peel should be avoided.
3. Clean and dry glass slide and coverslip should be used.
4. Coverslip should be put carefully avoiding any air bubbles.
To prepare a stained temporary mount of an onion peel and to record observations and draw labeled diagrams.
Apparatus and materials required:
An onion, glass slide, watch glass, coverslip, forceps, needles, brush, blade, filter paper, safranin, glycerine, dropper, water, and a compound microscope.
Theory:
All living organisms are made up of cells. The shape, size and the number of these units vary in organisms. The three major components of a cell are the cell membrane, cytoplasm and nucleus. In a plant cell, a cell wall surrounds the cell membrane.
Procedure:
1. Take an onion and remove its outermost peel.
2. Now cut a small part from an inner scale leaf with the help of a blade.
3. Separate a thin, transparent peel from the convex surface of the scale leaf with the help of forceps.
4. Keep this peel in a watch glass containing water?
5. Add two drops of safranin stain in the watch glass to stain the peel.
6. Take a clean slide and put a drop of glycerine in the centre of the slide.
7. With the help of a brush and needle transfer the peel on the slide. Glycerine prevents the peel from drying up.
8. Carefully cover it with a coverslip and avoid any air bubble from entering interring the coverslip.
9. Remove any excessive glycerine with a filter paper.
10. Observe the prepared mount of the peel under the low and high magnification of a compound microscope.
Observations:
A large number of rectangular cells are visible. These cells lie close to each other with intercellular spaces between them. These cells are surrounded by distinct cell walls. These cells have a dark stained nucleus and a large vacuole in the centre.
Precautions:
1. Overstaining and understaining should be avoid
2. Folding of the peel should be avoided.
3. Clean and dry glass slide and coverslip should be used.
4. Coverslip should be put carefully avoiding any air bubbles.
Answered by
34
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Take a few drops of safranin solution in a dropper and transfer this into another watch glass. Using a brush, transfer the peel into the watch glass containing the safranin solution. Let this remain in the Safranin solution for 30 seconds, so that the peel is stained.
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Hope it helps... ¯\_(ツ)_/¯
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