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प्रश्न
Give reasons/explain:
During the starch test, the leaf is boiled in methylated spirit.
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उत्तर
Boiling the leaf in methylated spirit removes chlorophyll, therefore it turns pale-white. The leaf is now brittle and stiff.
संबंधित प्रश्न
The diagram is set up to demonstrate an experiment. Pond weed was placed in five water-filled tubes. The experiment was set up as shown in the diagram. The tubes were then left for 24 hours. Write the correct answer out of the five available choices:
(i) In which tube would you except to find the plant with the least amount of starch?
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(ii) The tube in which most oxygen would be found is
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(iii) The tube in which least carbon dioxide would be found is
(a ) 1 (b) 2 (c) 3 (d) 4 (e ) 5
(iv) The tube in which the plant would survive for the shortest length of time is
(a ) 1 (b) 2 (c) 3 (d) 4 (e) 5

Given alongside is the diagram of an experimental set-up:

What alteration (s) will you make in it for obtaining expected result?
Given alongside is the diagram of an experimental set-up:

Would you take any step before starting the experiment? Describe this step and explain its necessity.
A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
Draw a neat diagram of a chloroplast and label its parts.
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 test-tubes are kept in sunlight. Answer the questions that follow:

(a) Name the physiological process that releases the bubbles of oxygen.
(b) Explain the physiological process as mentioned above in (a).
(c) What is the purpose of keeping a snail in test-tube B?
(d) Why does test-tube B have more bubbles of oxygen?
(e) Give an example of a water plant that can be used in the above experiment.
(f) Write the overall chemical equation for the above process.
ATP is needed for the dark reaction.
Give technical term:
Name the experiment to demonstrate the importance of light for photosynthesis.
Which of the following is used to remove chlorophyll from the leaves?
Match the terms given in column A with column B:
| Column A | Column B | ||
| (a) | Chlorophyll | (i) | Removes/absorbs CO2 |
| (b) | Methylated spirit | (ii) | Tests presence of starch |
| (c) | Potassium hydroxide | (iii) | Traps solar energy |
| (d) | Iodine solution | (iv) | Produces oxygen |
| (e) | Water | (v) | Bleaches chlorophyll |
