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Question
The diagram alongside represents a structure found in a leaf. Study the same and answer the questions that follow:
(i) Name the parts labeled A and B.
(ii) What is the biological term for the above structure?
(iii) What is the function of the part labeled A?
(iv) Mention two structural features of A, which help in the function mentioned in (iii) above?
(v) Where is this structure likely to be found in a leaf?
(vi) The structure (fig.5.22) helps in the process of transpiration. Explain the term transpiration.
(vii) How many other cells are found surrounding this structure as seen in the diagram?
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Solution
(i) A = Guard cell
B = Stomatal aperture
(ii) Stomata
(iii) The function of the guard cells are that they help to regulate the rate of transpiration by opening and closing the stomata thus preventing excessive water loss.
(iv) The two structural features of guard cells are :
1.The guard cells have thin outer wall and thick inner wall.
2. Guard cells contain chloroplast in their cytoplasm.
(v) These are present on the lower surface of the dorsiventral leaf.
(vi) Transpiration is the loss of water in the form of water vapour from aerial parts of the plant.
(vii) Five
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RELATED QUESTIONS
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Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with a suitable idea given in Column ‘I’.
| Column I | Column II |
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| (ii) Movement of water | (b) Stomata |
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Mark the most appropriate answer in the following:
Transpiration is very low during storms due to:
An outline sketch of a tree is shown in a diagram below. Study the same and answer the questions that follow:
- Name and define the phenomenon labelled A in the diagram.
- Write the significance of the process mentioned in A for the plants.
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- Draw a neat and labelled diagram of an opened stomata.
