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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
Define the following:
Plant pigments
The number of water molecules required in the chemical reactions to produce one molecule of glucose during photosynthesis is
Which one chemical reaction occurs during photosynthesis?
Are the following statement true or false? Give a reason in support of your answer.
The rate of photosynthesis continues to rise as long as the intensity of light rises.
All life on earth Would come to an end if there were no green plants.
Give technical term:
The main reaction which means the breaking up of water molecules through light.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Land plants obtain their CO2 from the atmosphere.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
A variegated leaf (one that has green as well as white patches) will only photosynthesize in the green areas.
Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with the suitable idea given in Column ‘I’.
| Column I | Column II | ||
| (i) | Grana | (a) | Decomposers |
| (ii) | Autotrophs | (b) | Light reaction |
| (iii) | By-products of photosynthesis | (c) | Animals |
| (iv) | Photolysis | (d) | Oxygen |
| (v) | Bacteria and fungi | (e) | Stimulated by light |
| (vi) | Chloroplast | (f) | Power |
| (vii) | Oxygen and water | (g) | Raw material |
| (viii) | Sunlight | (h) | Machinery |
| (ix) | CO2 and water | (i) | End products |
| (x) | Glucose (sugar) | (j) | Workrooms |
| (xi) | Cells in the leaf | (k) | By-products. |
Choose the correct option.
A cell that lacks chloroplast does not ______.
