Page 151 - August 2021

Subject: Biology
Topic: Transportation in plants
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Date: 18 August 2021
Activity: Purslane plant experiment to demonstrate roots absorb water and supply it to aerial
parts.
Roots absorb water and supply it to all the aerial parts. An experiment using 4 test tubes was
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demonstrated before them. All the test tubes were filled with 3/4 of water, except for the last
one.
1 test tube only had water and a cork was fixed at the mouth of the test tube. The second and
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third test tube had 3/4 of water with a layer of oil on top. In addition to it, few drops of ink were
added to the 3 test tube. Last test tube had only few drops of water. Now, the Purslane plant
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with roots thoroughly washed and in intact condition were introduced into 2 , 3 and 4 test
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tubes and left undisturbed for 2 days.
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The level of water remained the same in 1 test tube while the same reduced in 2 and 3 test
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tubes. Also, red colouration could be seen in the stem and leaves of the plant immersed in the
3 tube. The plant in 4 test tube was in a dried condition as the roots were not in contact with
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water and hence could not absorb water.
This proved that roots absorb water and supply it to the entire plant structure. In the same way,
leaves synthesise food and share it. Also, the different tissues in xylem function as a single unit
and lift water against the force of gravity and distribute it to upper parts of plant. This teaches
all of us to stay united in order to successfully accomplish any given task.