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प्रश्न
Look at leaves of the same plant on the shady side and compare it with the leaves on the sunny side. Or, compare the potted plants kept in the sunlight with those in the shade. Which of them has leaves that are darker green? Why?
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उत्तर
- Light is a limiting factor for photosynthesis. Leaves get less light for photosynthesis when they are in shade.
- Therefore, the leaves or plants in shade perform less photosynthesis as compared to the leaves or plants kept in sunlight.
- In order to increase the rate of photosynthesis, the leaves present in shade have more chlorophyll pigments.
- The pace of photosynthesis is accelerated by the leaves' increased ability to absorb light due to the rise in chlorophyll content.
- Therefore, the leaves or plants in shade are greener than the leaves or plants kept in the sun.
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संबंधित प्रश्न
Short answer question.
Which four of the following are needed for photosynthesis in a leaf:
(i) Carbon dioxide:
(ii) Oxygen:
(iii) Nitrates :
(iv) Water:
(v) Chlorophyll:
(vi) Soil:
(vii) Light:
Short answer question.
Which gas is taken in and which one is given out by the leaf in bright sunlight?
(i) Taken in :
(ii) Given out:
Suppose we compare the leaf with a factory, match the items in Column A with those in Column B.
| Column A | Column B | ||
| Left | Factory | ||
| 1 | Cells in the leaf | a | Raw materials |
| 2 | Chloroplast | b | Power |
| 3 | Sunlight | c | Machinery |
| 4 | Oxygen and water | d | End product |
| 5 | Carbon dioxide and water | e | By product |
| 6 | Glucose | f | Workroom |
State whether the following statement is True or False:
Green plants prepare their food by using two raw materials, oxygen and water.
State whether the following statement is True or False:
The free oxygen in the atmospheric air is the result of photosynthesis.
State whether the following statement is True or False:
Photosynthesis occurs only in chlorophyll-containing parts of the plant.
Long answer question.
In order to carry out photosynthesis, what are the substances that a plant must take in? Also mention their sources.
Long answer question.
What is the role of chlorophyll in photosynthesis?
Attempt any TWO of the following:
Describe ‘any two’ factors affecting the rate of photosynthesis.
Are the following statement true or false? Give a reason in support of your answer.
The outside atmospheric temperature has no effect on the rate of photosynthesis.
Two groups (A & B) of bean plants of similar size and same leaf area were placed in identical conditions. Group A was exposed to the light of wavelength 400-450 nm & Group B to light of wavelength of 500-550 nm. Compare the photosynthetic rate of the 2 groups giving reasons.
When there is plenty of light and a higher concentration of O2, what kind of pathway does the plant undergo? Analyse the reasons.
Photorespiration is favoured by :
Law of limiting factor is
Photosynthetic organisms occur at different depths in the ocean. Do they receive qualitatively and quantitatively the same light? How do they adapt to carry out photosynthesis under these conditions?
In tropical rain forests, the canopy is thick and plants growing below receive filtered light. How are they able to carry out photosynthesis?
According to Blackman, respiration of carbohydrates and fats is ______.
The figure shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following question:
- At which point/s (A, B or C) in the curve is light a limiting factor?
- What could be the limiting factor/s in Region A?
- What do C and D represent on the curve?

Graph of light intensity on the rate of photosynthesis
The optimum temperature for the process of photosynthesis is ______.
