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प्रश्न
Give scientific reasons : Balsam plants wilt during mid-day even if the soil is well watered.
उत्तर
In case of balsam plants, the rate of transpiration during mid-day exceeds the rate of absorption of water by the roots. The cells therefore lose turgidity. In the evening or during the night, the stomata are constricted and the temperature is not very high; therefore, there is no loss of water through transpiration, and the turgidity of the leaves is re-acquired.
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संबंधित प्रश्न
A plant cell may burst when :
The diagram below represents a process in plants. The setup was placed in bright sunlight. Answer the following questions:
a) Name the physiological process depicted in the diagram.
Why was oil added to the water?
b) When placed in bright sunlight for four hours, what do you observe with regard to the initial and final weight of the plant? Give a suitable reason for your answer
c) What happens to the level of water when this setup is placed in:
- Humid conditions?
- Windy conditions?
d) Mention any three adaptations found in plants to overcome the process mentioned in (i).
e) Explain the term ‘Guttation’.
Give the equivalent terms for the following:
Loss of water through a cut stem.
What is the difference between ‘flaccid’ and ‘turgid’? Give one example of flaccid condition in plants.
Give reason for the following:
It is better to transplant seedlings in a flower-bed in the evening and not in the morning.
Mention whether the following statement is true (T) or false (F) and give an explanation in support of your answer.
Soaked seeds burst into three seed coats.
The below diagram represents a plant cell after being placed in a strong sugar solution. Guidelines 1 to 5 indicate the following:
1. Cell wall
2. Plasma membrane.
3. Protoplasm
4. Large vacuole
5. Nucleus
Study the diagram and answer the questions that follow :
(i) What is the state of the cell shown in the diagram?
(ii) Name the structure which acts as a selectively permeable membrane.
(iii) If the cell had been placed in distilled water instead of a strong sugar solution which features: would not have been present?
(iv) If the cell in the diagram possessed chloroplasts where would these be present?
(v) Name any one feature of this plant cell which is not present in animal cells.
Give Technical Term for the following.
The pressure exerted by cell contents on a plant cell wall.
Name the following:
The process by which wilting or drooping of leaves occurs.
Excessive use of fertilisers in agricultural fields reduces the yield of crops. Justify the statement.
