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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.
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संबंधित प्रश्न
Give biological explanations for Plants growing in fertilized soil are often found to wilt if the soil is not adequately watered.
Mention two ways in which photosynthesis is useful to life.
Complete the following by filling in the blanks numbered 1 to 10 with the appropriate word/term:
Photosynthesis involves light reaction and dark reaction. During light reaction, the chlorophyll present in the (1) ______ gets activated by absorbing light energy. This energy splits (2) ______ molecules to (3) ______ and oxygen and releases two electrons. This process is called (4) ______. The (5) ______ ions are picked up by NADP to form (6) ______. The ADP is converted to (7) ______. This process is called (8) ______. During the dark phase, the compound produced at the end of the light reaction reacts with carbon dioxide to form (9) ______. This product is converted to starch. The process is called (10) ______.
Choose the correct answer:
Which one of the following is the best reason for leaving a plant in a dark place before carrying out experiments on photosynthesis?
Write the functional activity of the following structure:
Chloroplasts
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. |
Gas exchange takes place in plants using _____.
The end product of photosynthesis is ______.
The bending of shoot towards light is due to the hormone ______.
An organism A which cannot move from one place to another makes a simple food B from the substances C and D available in the environment. This food is made in the presence of green-colored substance E present in organs F in the presence of light energy in a process called G. Some of the simple food B also gets converted into a complex food H for storage purposes. Does this food give a blue-black color with iodine solution?
a. What is
- organism A
- food B?
- food H?
b. What are C and D?
c. Name green-colored substance E and organ F.
d. What is the process G?
