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प्रश्न
Oxygen given out during photosynthesis comes from water. Explain this statement.
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उत्तर
During the process of photolysis under light reaction, the water molecule split up to release H+ and OH– ions. These OH– react to liberate oxygen. Thus we can say that oxygen liberated during photosynthesis comes from water.
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संबंधित प्रश्न
Complete the following paragraph by filling in the blank (1) to (5) with appropriate words:
To test a leaf for starch, the leaf is boiled in water to (1) _________. It is then boiled in Methylated spirit to (2) ________. The leaf is dipped in warm water to soften it. It is placed in a petri dish, and (3) _____ solution is added. The region of the leaf which contains starch, turns (4) ________and the region while does not contain starch, turns (5) __________.
Match the terms of column I with those in column II:
| Column I | Column II |
| (i) Stomata closed | (a) decomposers |
| (ii) Autotrophs | (b) light reaction |
| (iii) By-products of photosynthesis | (c) animals |
| (iv) Photolysis | (d) during night |
| (v) Bacteria and fungi | (e) green plants |
| ( f) oxygen |
Which one chemical reaction occurs during photosynthesis?
A plant is kept in a dark cupboard for 48 hours before conducting any experiment on photosynthesis in order to
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.
Why was the plant kept in the dark before the experiment?
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.
Describe step by step, how the candidate proceeded to test the leaf for the presence of starch?
What is the importance of photosynthesis in the life of the following:
Green plants
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. |
Answer the following question.
Explain why photosynthesis is considered the most important process in the biosphere.
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?
