Advertisements
Advertisements
Question
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.
Solution
‘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.
RELATED QUESTIONS
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?
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:
Photosynthesis occurs only in chlorophyll-containing parts of the plant.
Long answer question.
What is the role of chlorophyll in photosynthesis?
Long answer question.
Do plants need oxygen? If so, what is its source?
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?
Why does the rate of photosynthesis decrease at higher temperatures?
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 ______.
