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प्रश्न
The given figure represents an experiment:
- Leaf A was coated with grease on both surfaces.
- Leaf B was coated with grease on the lower surface.
- Leaf C was coated with grease on the upper surface.
- Leaf D was left without any application of grease. All four leaves A, B, C and D were left in a room for about 24 hours.
- Which leaf dries first? Give reason.
- Which leaf dries last? Give reason.
उत्तर
- Leaf D: the leaf with no greasing on either surface would dry first, as it would shed the maximum amount of water from both surfaces.
- Leaf A: The leaf that was greased on both surfaces would dry out due to the fact that grease prevents water evaporation and transpiration by means of stomata, which are more prevalent on the lower surface of the leaf.
संबंधित प्रश्न
Give Reasons for the following:
Guard cells are small in size and are kidney-shaped in outline.
Explain the Term
Stomatal transpiration
Differentiate Between Stomata and Hydathodes.
Given below are the diagrams of a certain structure in plants in two conditions.
(i) Name the structure shown.
(ii) Name the parts numbered 1-5.
(iii) What is the most apparent difference between A and B in the structure shown?
(iv) Describe the mechanism which brings about the change in the structure depicted in A and B.
The apparatus shown here is Girreau’s poto-meter designed to demonstrate unequal transpiration from the two surfaces of a dorsiventral leaf. Before keeping the leaf in between the cups, anhydrous calcium chloride (CaCl2) contained in two small vials were weighed and placed in both the cups. The ends of the cups were closed with corks through which two mercury manometers were connected. After a few hours, CaCl2 vials were taken out and weighed again.
(i) What is the purpose of keeping CaCl2 vials inside the cup?
(ii) After a few hours, the CaCl2 vials were taken out and weighed again. Will you expect any difference in weight? If so, give reasons.
(iii) What was the purpose of using a mano-meter?
(iv) What do you mean by transpiration?
Draw a neat diagram of the stomatal apparatus found in the epidermis of leaves and label the Stoma, Guard cells, Chloroplast, Epidermal Cells, cell wall and Nucleus.
Give Technical Term
Which side of the leaf has more stomata?
Assertion (A): The loss of excess water from the aerial parts of the plant in the form of water vapor is known as transpiration.
Reason (R): Stomata of the leaf perform transpiration.
Write a short note on lenticular transpiration.
Give a reason/suitable explanation.
Leaves of some plants wilt during midday and recover in the evening.
