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Question .1. Name the following : (i) The respiratory openings found on stems of woody plants. (ii) An apparatus to compare the rate of transpiration in cut shoots. (iii) The process by which intact plants lose water in the form of droplets. (iv) Opening on the stem through which transpiration occurs. (v) Opening found on the under surface of dorsiventral leaves. (vi) The paper which is used to show loss of water through stoma of a leaf. (vii) An instrument used for measuring the rate of transpiration. (viii) The structure through which most of the transpiration takes place. (ix) The process of loss of water in the form of droplets. (x) The structure through which guttation takes place. (xi) The kidney-shaped cells present on stomata. (xii) The plant having sunken stomata. (xiii) The chemical used to prevent excessive transpirationin plants. Question .2. State true or false : (i) Low humidity in the atmosphere results in a decrease in the rate of transpiration. (ii) Transpiration takes place only in the green plants. (iii) The wall of a guard cell towards the stoma is thin. (iv) Leaves are reduced to spines in xerophytic plants. (v) The loss of water droplets is called bleeding. (vi) The pH of the guard cells increase during day time. (vii) The escape of plant-sap from the cut surface is called guttation Question .3. Give the technical terms for the following : (i) Loss of water in the form of water droplets from the margin of leaves. (ii) Transports manufactured food from leaves to other parts of the plant. Question .4. Define the following : (i) Transpiration (ii) Guttation. Question .5. Explain briefly : (i) Xerophytes have their leaves modified to spines or reduced in size. (ii) A higher rate of transpiration is recorded on a windy day rather than on a calm day. (iii) During the day transpiration and photosynthesis are interlinked. Question .6. Briefly explain how the rate of transpiration is affected by : (i) Intensity of light. (ii) Humidity of the atmosphere Question .7. Choose the correct alternative : (i) Transpiration pull will be maximum under which of the following conditions : (open stomata, dry atmosphere and moist soil; open stomata, high humid atmosphere and well irrigated soil; open stomata, high humid atmosphere and dry soil; closed stomata, dry atmosphere and dry soil). (ii) Loss of water as droplets through leaves of an intact plant is termed (bleeding, guttation, transpiration). Question .8. Describe any three conditions which affect transpiration. Question .9. 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 Question .10. 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 : Fig. (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 are glass slides placed over the dry cobalt chloride paper ? (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. Question .11. The diagram shown below is an apparatus used to study a particular phenomenon in plants : Fig. (i) Name the apparatus. (ii) What is used for ? (iii) What is the role played by the air-bubble in this experiment ? (iv) Of what use is the reservoir ? (v) Mention one limitation of this experiment. (vi) Which phenonmenon is studied with the help of this apparatus ? (vii) What happens to the movement of the air-bubble if the apparatus is kept : 1. In the dark. 2. In sunlight. 3. In front of a fan. Give a reason in each case. Question .12. Study the diagram given below and answer the questions that follow : (i) Explain the physiological process being studied. (ii) What will be observed in the two test tubes after two to three days ? (iii) Give the reason for your answer in (ii) above. (iv) Why is the surface of water covered with oil ? (v) State the purpose of setting up test tube B.
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