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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
Two healthy green plants were placed in the dark for 24 hours. They were then set up, as shown in the figure, for 4 hours. Then a leaf was taken from each plant and
the chlorophyll was removed from the leaves:
( i) What is the next and final step in this experiment?
( ii ) What would be the results of the final step?
( iii ) Why was it necessary to grease the glass sheet?
( iv ) What hypothesis is being tested in this experiment?
Complete the following statement by choosing the correct alternative given below :
All animals would die on the earth if there was no ______.
The chemical substance used to test the presence of starch in the cell of a leaf is ______.
How would you demonstrate that green plants release oxygen when exposed to light?
Photosynthesis in green plants is directly and indirectly dependent on so many plant structures.
Explain briefly the role of the following structures in this process is Xylem tissue in the leaf veins
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.
During the starch test, why was the leaf
(1) boiled in water
(2) boiled in methylated spirit
Complete the following sentence with appropriate word:
________ are regarded as complete photosynthetic units of plants.
Write the overall chemical equation for photosynthesis.
Given below is the diagram of an experimental set-up (final stage). Study the same and answer the following questions:
- What is the main aim of the experiment?
- Oxygen gas shown in the experiment is released from which of the raw materials?
- How would you confirm the presence of oxygen gas?
- Name the chemical substance which can be added in water to enhance the process/rate of release of oxygen gas.
- Draw a neat and labelled diagram of the same experiment for its initial stage.
