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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.
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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
Distinguish between the following:
Stomata and lenticels
State the functions of guard cells.
What is the advantage of wilting to a plant?
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.
Given below is the diagram of an experimental set up to study the process of transpiration in plants. Study the same and then answer the questions that follow:
(i) What is the colour of dry cobalt chloride paper?
(ii) Is the experimental leaf a monocot or a dicot? Give a reason to support your answer.
(iii) Why axe glass slides placed over the dry cobalt chloride papers?
(iv) After about half an hour what change, if any, would you expect to find in the cobalt chloride paper placed on the dorsal and ventral sides of the leaf? Give a reason to support your answer.
(v) Define the term ‘transpiration’.
Draw a labeled diagram of the stomatal apparatus and label the following in it: Stoma, Guard cells, Chloroplast, Epidermal cells, and Cell wall.
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.
Name the following:
The process of getting rid of excess water in the form of water vapour through the stomata.
