Study of distribution of stomata

 

 Lab Procedure

• Pluck one fresh leaf of a four-o’clock plant.
• Take two watch glasses and pour some distilled water into the both watch glasses.
• Split the leaf from the four-o’clock plant obliquely.
• Take the peel from the upper surface of the leaf using the forceps.
• Place the peel into a watch glass containing water.
• Take another peel from the lower surface of the leaf using the forceps.
• Place the peel into the other watch glass containing water.
• Using a dropper, take few drops of Safranin solution and put it into the two watch glasses.
• Take two clean glass slides and place the leaf peel on the slides one by one, using a brush.
• Take a blade and cut a small rectangle or square piece from each peel.
• Take some glycerine using a dropper and put one drop of glycerine on both slides.
• Take a cover slip and place it gently on the peel with the help of a needle.
• Take the glass slide and place it under compound microscope.
• Observe under the microscope.
• Count the number of stomata in the peels of both upper and lower epidermis of the leaf appearing in the microscopic field.

Observations

• The number of stomata is greater in the lower epidermis, and fewer are present in the upper epidermis of the leaf taken from a four-o’clock plant.

Precautions

• The curling of the peel should be avoided.
• Always use a brush to transfer the peel from watch glass to the slide