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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
With decrease in atmospheric pressure, the rate of transpiration will(a) increase(b) decrease rapidly(c) decrease slowly(d) remain the same |
| Answer» (a) increase. | |
| 52. |
Transpiration pull will be maximum under which set of the following conditions?(a) Open stomach, dry atmosphere and moist soil.(b) Open stomata, high humid atmosphere and well irrigated soil.(c) Open stomata, high humid atmosphere and dry soil.(d) closed stomata, dry atmosphere and dry soil. |
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Answer» (a) Open stomata, dry atmosphere and moist soil |
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| 53. |
Describe any three conditions which affect transpiration. |
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Answer» The three conditions which affect transpiration are the following : 1. Sunlight: In bright sunlight, the stomata remain fully open and transpiration takes place through the stomatal pores. At night stomata remains closed, so transpiration is reduced. 2. Wind: If the Wind velocity is high, transpiration becomes rapid because the water vapour is carried away before the air around the leaf becomes saturated. 3. Available water: If available water in the soil is low, the transpiration is low and the leaves may even begin to wilt. |
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| 54. |
What are the disadvantages of transpiration ? |
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Answer» (i) Some plants will die due to excessive water loss by transpiration. (ii) Due to high rate of transpiration plant suffer from loss of turgidity. |
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| 55. |
What are the advantages of transpiration to the plant? |
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Answer» (i) It results in ascent of sap by creating a suction force. (ii) It results in cooling of the plant in summer. (iii) It helps in distribution of water to all parts of the plants. (iv) It helps in elimination of excess of water absorbed by the roots. |
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| 56. |
The figure below represents the vertical section of a leaf:(i) Name the parts labeled 1 to 5.(ii) What do the two arrows (dotted and solid) indicate in the day time and at night ?(iii) Could you add one more arrow in the figure ? If yes, what for ?(iv) How many leaf veins have been shown in this section ? |
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Answer» (i) 1. Cuticle, 2. Upper epidermis, 3. Palisade tissue, 4. Spongy parenchyma, 5. Guard cell of stoma. (ii) In the day time dotted arrow shows the path of CO2 while solid arrow shows the path of oxygen. A night dotted arrow shows the path of oxygen while solid arrow shows the path of CO2. (iii) Yes, we can add one more arrow in the figure to show the loss of water during transpiration. (iv) Only one leaf vein has been shown in this section. |
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| 57. |
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. |
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Answer» (i) Stomata surrounded by epidermal cells. (ii) 1. Chloroplast, 2. Inner wall of guard cells, 3. Nucleus, 4. Guard cells, 5. Stoma. (iii) The stoma is open in A and is almost closed in B. (iv) The opening and dosing mechanism of stomata is regulated by the amount of water and solutes present in the guard cells. The guard cells have a thick inner wall facing the opening and a thin outer wall on the opposite side; their cytoplasm contains chloroplasts. During the day guard cells begin photosynthesis and the sugar produced during the process increases the osmotic pressure which draws in water from the adjoining cells. Hence, the guard cells become turgid and bulge outward due to their thin outer wall, thus widening the stomatal opening lying in between (Fig. A). As the stomata open, the diffusion of gases in and out begins for fulfilling the need for photosynthesis and for allowing transpiration. If for any reason the water content of the leaf is falling short, the guard cells fail to remain turgid, they turn flaccid or lose turgidity, thereby closing the stomatal opening (Fig. B) and the transpiration stops. |
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| 58. |
The diagram below represents a structure found in a leaf.Study the same and answer the questions that follow:(i) Name the pis 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 above structure 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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Answer» (1) A—Guard cell B—Stoma. (ii) Stomatal apparatus. (iii) Regulates opening & dosing of Stomata. (iv) Gives rigidity and protection to the cell. (v) On the epidermis of leaf. (vi) Transpiration is the loss of water as water vapours from the aerial parts of the plant. (vii) Five. |
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| 59. |
Given below is an example of a certain structure and its special functional activity:Chloroplasts and Photosynthesis.In a similar way, write the functional activity against each of the following:(a) Hydathodes and ……………………….(b) Leaf spines and …………………………(c) Lenticels and ……………………………(d) Thick cuticle and ……………………….. |
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Answer» (a) guttation (b) protection and reduced transpiration (c) transpiration (d) reduced transpiration |
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| 60. |
Given below is an apparatus used to study a particular process in plants. Study the same and answer the questions that follow :(i) Name the apparatus.(ii) Mention one limitation of this apparatus.(iii) Which phenomenon is studied with the help of this apparatus?(iv) What is the function of the part marked ‘reservoir’?(v) What is the role of the air bubble in the experiment? |
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Answer» (i) Garreau’s Potometer. (ii) The capillary tube should be properly dipped into the water. (iii) Transpiration. (iv) It is used to ad just the position of air bubble in graduated capillary tube. (v) The movement of air bubble in graduated tube in a minute gives the rate of transpiration. |
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| 61. |
Given below is an experimental set up to study a particular process :(i) Name the process being studied.(ii) Explain the process named in (i) above.(iii) Why is the pot covered with a plastic sheet ?(iv) Mention one way in which this process is beneficial to the plant.(v) Suggest a suitable control for this experiment. |
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Answer» (i) Transpiration. (ii) It is process in which water in the form of vapours are released from the aerial parts like leaves and soft stems of the plant. (iii) The plastic she et will not allow the moisture of the mud of the pot to come out and affect the result. (iv) It helps in ascent of sap in the plant. (v) A similar apparatus is set up without the potted plant. In its place a same plastic bag, with its mouth tied, is kept in the bell jar. No water drops will appear in the bell jar. |
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| 62. |
The figure given below represents an experimental set up with a weighing machine to demonstrate a particular process in plants. The experimental set up was placed in bright sunlight. Study the diagram and answer the following questions:(i) Name the process intended for study.(ii) Define the above mentioned process .(iii) When the weight of the test tube (A & B) is taken before and after thee experiment, what is observed ? Give reasons to justify your observation in A & B.(iv) What is the purpose of keeping the test tube B in the experimental set up? |
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Answer» (i) Transpiration. (ii) It is the release of water vapours from the aerial parts of the plant. (iii) Weight of test tube A will decrease after the experiment because water will be lost from it through the leaves by transpiration. Weight of test tube B will remain same after the experiment because water will not be lost by transpiration as there is no plant in and nor by evaporation as oil is spread over it, which will not allow evaporation. (iv) It is a control experiment where the purpose of using test tube B is to compare the level of water in both test tubes. |
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| 63. |
Give suitable explanation for the following:a) A higher rate of transpiration is recorded on a windy day rather than on a calm day.b) Excessive transpiration results in the wilting of the leaves.c) Water transpired is the water absorbed.d) More transpiration occurs from the lower surface of a dorsiventral leaf.e) Cork and bark of trees help in preventing loss of water.f) Perspiration and transpiration help to cool the body temperature of the organism.g) On a bright sunny day, the leaves of certain plants roll up. |
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Answer» a) Transpiration increases with the velocity of wind. If the wind blows faster, the water vapours released during transpiration are removed faster and the area surrounding the transpiring leaf does not get saturated with water vapour. b) When the rate of transpiration far exceeds the rate of absorption of water by roots, the cells lose their turgidity. Hence, excessive transpiration results in wilting of the leaves. c) Plants absorb water continuously through their roots, which is then conducted upwards to all the aerial parts of the plant, including the leaves. Only a small quantity of this water i.e. about 0.02% is used for the photosynthesis and other activities. The rest of the water is transpired as water vapour. Hence water transpired is the water absorbed. d) There are more stomatal openings on the lower surface of a dorsiventral leaf. More the number of stomata, higher is the rate of transpiration. Hence more transpiration occurs from the lower surface. e) Cork and Bark of trees are tissues of old woody stems. Bark is thick with outermost layer made of dead cells and the cork is hydrophobic in nature. These properties make them water-proof and hence they prevent transpiration. f) In both perspiration and transpiration, water is lost by evaporation from the body of the organism as water vapour. This evaporation reduces the temperature of the body surface and brings about cooling in the body of the organism. g) On a bright sunny day, the rate of transpiration is much higher than any other days. The leaves of certain plants roll up on a bright sunny day to reduce the exposed surface and thus reduce the rate of transpiration. |
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| 64. |
Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with the suitable idea given in Column ‘I’.Column IColumn II(i) Transpiration(a) Cacti plants(ii) Movement of water(b) Stomata(iii) Guttation(c) Maize plant(iv) Low rate of transpiration(d) Xylem(v) High rate of transpiration(e) Hydathodes |
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| 65. |
Holes present on the surface of the stems and twigs for transpiration. Name it. |
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Answer» Holes present on the surface of the stems and twigs for transpiration is Lenticels. |
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| 66. |
Season in which transpiration rate is the highest. |
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Answer» Transpiration rate is the highest in Summer Season. |
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| 67. |
The process of getting rid of excess water in the form of water vapour through the stomata. Name it. |
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Answer» Transpiration |
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| 68. |
The loss of water as water vapour from the acrial parts of a plant is known as(a) evaporation(b) perspiration(c) guttation(d) transpiration |
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Answer» (d) transpiration |
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