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प्रश्न
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.
उत्तर
‘A’ group of plants exposed to light of 400 - 450nm. Chlorophyll a shows maximum absorption peak at 450nm (blue region). Hence rate of photosynthesis was high.
‘B’ group of plants exposed to light of 500 - 550nm. This wavelength refers to green region of the spectrum. Chlorophyll does not absorb light in the green region but reflects green. So plants appear green rate of photosynthesis was negligible in these plants.
संबंधित 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?
Short answer question.
Why do leaves generally look green?
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:
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:
The chlorophyll enables the plants to use light energy.
State whether the following statement is True or False:
The free oxygen in the atmospheric air is the result of photosynthesis.
Long answer question.
What is the role of chlorophyll in photosynthesis?
Long answer question.
Do plants need oxygen? If so, what is its source?
Answer the following in one word.
Which organ is called the voice box?
Attempt any TWO of the following:
Describe ‘any two’ factors affecting the rate of photosynthesis.
Identify the false statement and rewrite it correctly by changing the first or last word only.
Photosynthesis requires enzymes.
Identify the false statement and rewrite it correctly by changing the first or last word only.
Photosynthesis stops at a temperature of about 35°C.
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.
In tropical rain forests, the canopy is thick and plants growing below receive filtered light. How are they able to carry out photosynthesis?
Why does the rate of photosynthesis decrease at higher temperatures?
According to Blackman, respiration of carbohydrates and fats is ______.
The optimum temperature for the process of photosynthesis is ______.
