Stomata Vs Chlorophyll
It is easy to identify the difference between Stomata and the Chlorophyll. However sometimes children get confused or mixed up when facing examination questions.
One of the common misconception is that stomata takes in sunlight and I cannot stress enough that this is not true!
Even though school curriculum teaches students that Stomata are found mostly on the underside of the leaves, students have to bear in mind that this does not apply to ALL type of plants.
So, what type of plants are an exception to this concept?
ANSWER IS THE FLOATING PLANTS
Why?
This is because the lower surface is constantly in contact with water while the upper surface is in constant contact with air , so it's more difficult for gaseous exchange to occur at that lower surface as compared to the upper one
Therefore,
Stomata are mostly found on the underside sides of the leaves for LAND PLANTS
but Stomata are mostly found on the upperside of the leaves for FLOATING PLANTS
Try answering some questions
1. What happens if a person cover all the leaves of a plant with a layer of oil?
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2. Why are the stomata mostly found on the underside of the leaves?
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3. John carried out an experiment by covering part of a leaf with black paper as shown below.
After a few weeks, he conducted a starch test by applying iodine solution to the leaf and observed that the area covered by the black paper and the white area of the leaf did not turn dark blue.
Explain his observations.
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Answers
1. The plant will die after some time. The layer of oil blocks the stomata of the leaves, causing the plant to be unable to take in carbon dioxide for photosynthesis to make food. Hence it will die.
2. Lesser water vapour will be lost through transpiration as the stomata are less exposed to the sun in the cooler, shady underside of the leaf.
3. The black paper do not allow light to pass through, hence the area covered by the black paper will not be able to trap sunlight to photosynthesise and make food for the plant which will be stored as starch.
The white area of the leaf do not contain chlorophyll hence it cannot trap sunlight to photosynthesise and make food for the plant which will be stored as starch. Therefore the iodine solution remains brown and not turn dark blue.
