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प्रश्न
A candidate studied the importance of certain factors in photosynthesis. He took a potted plant and kept in the dark for over 24 hours. In the early hours of the next morning, he covered one of the leaves with black paper in the centre only. Then he placed the plant in sunlight for a few hours and tested the leaf which was covered with black paper for starch.
Describe step by step, how the candidate proceeded to test the leaf for the presence of starch?
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उत्तर
- The student dipped the leaf in boiling water for a minute to kill the cells.
- Then he boiled the leaf in alcohol/methylated spirit over a water bath to remove chlorophyll. The leaf becomes hard and brittle.
- He then places the leaf in hot water to soften it.
- Next the student spreads the leaf in a dish and pours iodine solution on it. The presence of starch is indicated by a blue-black colour.
- The uncovered portion (exposed to sunlight) turned blue-black colour and the covered portion showed brown colour. The difference in the colours of covered and uncovered part of leaves indicates the importance of sunlight in photosynthesis.
संबंधित प्रश्न
Given below is an experiment setup to demonstrate a particualr tropic movement in germinating seeds. Study the diagram and answer the questions that follow :
(ii) Name the tropic movement shown by part 1.
How does carbon dioxide return to the atmosphere? Explain.
A student in order to study the importance of certain factors of photosynthesis took a potted plant and kept it in the dark for over 24 hours. Then in the early hours of the morning the student covered one of the leaves with black paper in the centre only. Student placed the potted plant in the sunlight for a few hours, and then tested the leaf which was covered with black paper for starch.
(i) What aspect of photosynthesis was being investigated?
(ii) Is there any control in this experiment? If so, state the name.
(iii) Why was the plant kept in the dark before the experiment?
(iv) Describe step by step how the candidate proceeded to test the leaf for the presence of starch.
If the rate of respiration becomes more than the rate of photosynthesis, plants will:
The specific function of light energy in the process of photosynthesis is to
Name the following:
The tissue that transports manufactured type of starch from leaves to all parts of the plants.
Complete the following food chain by writing the names of appropriate organisms in the blank:
Grass → __________ → Lion
Explain the Term Free Energy.
Choose the correct option.
The sequential order in electron transport from PSII to PSI of photosynthesis is ______.
State whether true or false. If false, correct the statement.
Plants lose water when the stomata on leaves are closed.
Name the plant part
- Which bends in the direction of gravity but away from the light.
- Which bends towards light but away from the force of gravity.
