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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
The individual flattened stacks of membranous structures inside the chloroplasts are known as :
A. Grana
B. Stroma
C. Thylakoids
D. Cristae
The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both testtubes are kept in sunlight. Answer the questions that follow:
(i) Name the physiological process that releases the bubbles of oxygen.
(ii) Explain the physiological process as mentioned above in Q2 (a)(i).
(iii) What is the purpose of keeping a snail in test-tube ‘B’?
(iv) Why does test-tube ‘B’ have more bubbles of oxygen?
(v) Given an example of a water plant that can be used in the above process.
(vi) Write the overall chemical equation for the above process.
Define the following:
Plant pigments
Name the following:
The cell organelle responsible for photosynthesis.
The following statement is about photosynthesis in a green plant. Write whether it is True or False.
Land plants obtain their carbon dioxide from the atmosphere.
During photosynthesis, the oxygen in glucose comes from
What is the importance of photosynthesis in the life of the following:
Green plants
Give technical term:
What is the percentage of CO2 in the air?
The minerals like nitrogen, potassium, and phosphorus, which are required in substantial quantity by the plants are called ______.
Guard cells of stomata are green but cannot photosynthesize? Give reason.
