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प्रश्न
Given below is the figure of an experimental set-up, showing a physiological act of the plants. Study and answer the following questions:
- What is the objective of this experiment?
- Name and define the process shown here.
- Why do we destarch the leaves before performing the experiment?
- How do we destarch the leaves?
- What will be the observation when we pour iodine solution over the bleached experimental leaf?
- Write a well-balanced equation for the above process.
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उत्तर
- To demonstrate the need for sunlight for photosynthesis.
- Photosynthesis. Photosynthesis is the process by which plants produce glucose using water, carbon dioxide, sunshine, and chlorophyll pigment in their leaves. Photosynthesis produces glucose and oxygen as its end products. Plants use glucose to power their cells, while other species require oxygen for respiration.
- We remove starch from a plant to facilitate photosynthesis in the presence of sunlight. If starch is already present in the leaves, photosynthesis does not take place.
- By keeping the leaves in a dark room for 24 to 48 hours, we can destarch them. This is because darkness inhibits photosynthesis and enables the plant to use up any stored starch.
- If starch is present, the bleached experimental leaf will turn blue-black when iodine solution is applied. The leaf is said to be starch-free if there is no colour change and it stays brown.
- \[\ce{6CO2 + 6H2O ->[Sunlight][Chlorophyll] C6H12O6 + 6O2}\]
संबंधित प्रश्न
A healthy oat seeding in a pot is transferred from light to any airy but completely dark room. How would it differ from its original condition in appearance after about a week? Explain the difference.
Are the following statement true or false? Give a reason in support of your answer.
Destarching of the leaves of a potted plant can occur only at night.
Complete the following by filling the blanks 1 to 5 with appropriate words/terms/phrases:
To test the leaf for starch, the leaf is boiled in water to ______ (1). It is next boiled in methylated spirit to ______ (2). The leaf is placed in warm water to soften it. It is then placed in a dish and ______ (3) solution is added. The region which contains starch, turns ______ (4) and the region which does not contain starch, turns ______ (5)
Given alongside is the diagram of an experimental set-up:
Will it work satisfactorily? Given reason.
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.
Write a balanced chemical equation to represent the process of photosynthesis.
Name the following:
The site of light reaction in the cell of a leaf.
Choose the Odd One Out
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 |
