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प्रश्न
The figure given below is for performing an experiment on photosynthesis.

Answer the following:
(i) What is the aim of this experiment?
(ii) Describe an experiment to show that light is necessary for photosynthesis.
(iii) What do you conclude from this experiment?
(iv) What is the role of light in photosynthesis?
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उत्तर
- To demonstrate that sunlight is necessary for photosynthesis.
- Take a potted plant and keep it for 2-3 days in dark to destarch its leaves. Take one leaf and cover it on both sides with two black paper strips, as shown in the diagram, with the help of cellophane tape. Now keep the potted plant in light. After a few hours pluck the leaf and remove the black strips. Boil the leaf in alcohol and wash it in water. Test the leaf for starch with iodine solution. The leaf turns blue all over except the region covered with black stripes. This shows that the region which did not receive light could not synthesise starch. Thus, light is necessary for photosynthesis.
- Light is necessary for photosynthesis.
- Light supplies energy in the form of photons to split water during tight reaction.
संबंधित 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.
Is there any control in this experiment? If so, state it.
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 Phloem tissue in the leaf veins.
All life on earth Would come to an end if there were no green plants.
Name the following:
Source of oxygen given out in photosynthesis.
Give technical term:
Organisms which cannot prepare their own food by photosynthesis.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Photosynthesis can also occur n artificial light such as that of a 100-watt electric lamp.
Gas exchange takes place in plants using _____.
What will happen if you breathe through mouth?
The end product of photosynthesis is ______.
