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प्रश्न
State the utility of oxygen for respiration in plants
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उत्तर
Respiration in plants:
- Plants respire during the day and night.
- Plants respire through tiny pores on the surface of the leaves called ‘stomata’.
- The stomata help in taking in the oxygen of the air and giving out carbon dioxide. Thus, they function as respiratory organs.
- Plants do not perform bodily activities and hence need less energy than animals. The rate of respiration in plants is thereby slower than in animals.
Photosynthesis in plants:
Photosynthesis is a process by which green plants prepare their own food in the presence of sunlight and chlorophyll.
- In the leaf of a green plant are present leaf cells which contain chloroplasts in which is present a green pigment called chlorophyll.
- During photosynthesis which occurs during daytime, carbon dioxide and water in the presence of sunlight and chlorophyll is changed into glucose, and oxygen is released out.
\[\ce{Carbon dioxide + Water ->[Sunlight][Chlorophy II]Glucose + Oxygen + Water}\] - Hence oxygen in the air is renewed by photosynthesis and therefore the amount of oxygen in the air does not get depleted or removed from the air.
संबंधित प्रश्न
What are the two ways in which nitrogen fixation occurs?
Write ‘True’ or ‘False’ in front of following statement.
Enamelling is the process of baking a mixture of silicates on the surface of aluminium at a high temperature.
With the help of a labeled diagram, describe a simple experiment to show the presence of oxygen and nitrogen in air using a piece of white phosphorus.
You are given a test tube with two outlets and a bottle of lime water. Using same, how would you demonstrate experimentally the presence of carbon dioxide in air.
Match the statements in List 1 with the correct answers in List 2
| List 1 | List 2 | ||
| 1 | An impurity in air | A | Water vapour |
| 2 | The component of air which supports combustion | B | Respiration |
| 3 | The inert component in the air slightly soluble in water | C | Rare gases |
| 4 | The component of air which minimizes the rate of evaporation | D | Sulphur dioxide |
| 5 | The process which involves oxidation of food substance in living organisms | E | Helium |
| 6 | The component of air which finds application in observation balloons | F | Carbon dioxide |
| 7 | The process which involves oxidation of substances, liberating heat and light energy | G | Combustion |
| 8 | The component of air which is heavier than air and fairly soluble in water | H | Nitrogen |
| 9 | The process by which atmospheric carbon dioxide is absorbed by plants resulting in the formation of carbohydrates | I | Photosynthesis |
| 10 | The component of air which is lighter than air and less than 1% in air | J | Oxygen |
The diagrams below represents an experiment to show the presence of a component of air.
- State why air is sucked from – outlet ‘B’ and not from outlet “A”
- State why the air is sucked ‘slowly’ from the outlet “B”
- State the observation seen after completion of the experiment.
- State the reason for the above observation seen.
- Name another component which if present in air as a pollutant would have given a similar observation
State whether the following statement is ‘true’ or ‘false’. If false write the correct statement.
Photosynthesis is a process by which green plants prepare their own food in the presence of sunlight and chlorophyll.
Inhaled air contains a large amount of carbon-di-oxide.
______ is the main component of air.
Venus's atmosphere consists of roughly 96 – 97% of ______.
