2. Which of the following statements are true and which ones are false? These properties make them water-proof and hence they prevent transpiration. The root pressure generated by a plant assists in bleeding. Now, keep all the three bell jars together in the sun. The purpose of keeping the test tube B in the experimental setup this makes the observation of the change in test tube A easy. Only a small quantity of this water (about 2%) is used by the plant in photosynthesis and other activities. (D) left uncoated. 1. In both perspiration and transpiration, water is lost by evaporation from the body of the organism as water vapour. Cork and bark of trees help in preventing loss of water. Comment upon your answer. More than 10% of the earth’s moisture is from transpiration. There are more stomatal openings on the lower surface of a dorsiventral leaf and therefore, more transpiration occurs from the lower surface. The transpiration rate of commodities often declines over time after harvest. asked Aug 31, 2018 in Biology by AnujPatel (53.4k points) transpiration; class-10; 0 votes. Fill in the blanks: Are these dew drops? Why are the stomata in most plants more numerous on the lower surface of a leaf instead of being on the upper surface? Students of Class 10 are suggested to practice Selina Solutions to strengthen the fundamentals and be able to solve questions that are usually asked in the examination. The transpiration rate will increase. Transpiration is the evaporation. A humid environment hampers transpiration while the roots continue to absorb water from the soil. Transpiration is the loss of water in the form of water vapour from the leaves and other aerial parts of the plant. Potometer is an instrument used to find the rate of transpiration. So, excessive transpiration results in wilting of the leaves. The purpose of putting oil in the test tube is to prevent the loss of water by evaporation. What is lenticular transpiration? Lenticels are special opening that develops on the barks of the older stem in place of stomata. Hence a huge amount of water is escaped into the atmosphere by forests. As transpiration proceeds, i.e., as the water is lost from the twig, a suction force is set up which pulls the water from the beaker and the bubble in the capillary tube moves along. In tomato, after a 14-day storage period, transpiration was reduced by 50% of its initial value (Díaz-Pérez and Araiza, 1997).The causes of this reduced transpiration rate are probably due to increased resistance to water movement inside the commodity from the commodity to the outside air as the commodity dehydrates. It is the removal of water from the plant because of injury. The air bubble can be brought back to its original position by releasing some more water from the reservoir the capillary tube by opening the stop cock. Given below is an example of a certain structure and its special functional activity: In a similar way, write the functional activity against each of the following: So no water is lost from the leaf through transpiration since the stomatal openings get blocked by vaseline. Of the transpired water passing through a plant only 1% is used in the growth process. Droplets of water were then seen inside the bell jar. (b) What is the purpose of putting oil in the test tube? Most of the transpiration in tall trees occurs through (a) Stomata (b) Lenticels (c) Cuticle (d) Bark. Transpiration increases with the velocity of wind. Transpiration is the process of water moving through plants and its evaporation from leaves, stems and flowers. Transpiration takes place through stomata. An apparatus as shown below was set up to investigate a physiological process in plants. Experiment to demonstrate the transpiration phenomenon with the bell jar method: ADVERTISEMENTS: Requirements: Bell jar, well-watered potted plant, rubber sheet, glass plate, Vaseline. More transpiration occurs from the lower surface of a dorsiventral leaf. ICSE Rankers is a free educational platform for icse k-12 students. Question A.8. (f) List three adaptations in plants to reduce the above mentioned process. 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. Plants regulate transpiration by opening and closing stomata, but transpiration is also influenced by environmental conditions around the leaf. 5. Justify. Fewer stomata:- The number of stomata may be reduced. 1 answer. Stomates are necessary to admit carbon dioxide for photosynthesis and to release oxygen, hence transpiration is generally considered to be merely an unavoidable phenomenon that accompanies the real functions of … The figure given below represents an experimental setup with a weighing machine to demonstrate a particular process in plants. (c) The structure of stoma remains same in monocots as well as in dicots. 5. Name the following: The stomatal pores open and close in response to environmental changes and conditions within the plant, and they play an important role in regulating transpiration. Enclose the pot completely within a polythene bag and tie the mouth of the bag firmly around the base of the stem. In some plants, e.g. Related questions. (d) A plant in which the stomata are sunken. Hence, the stoma from the diagram can be of a monocot leaf or of a dicot leaf. It evaporates most of the water and allows more molecular space for more to come. At 30°C, a leaf may transpire three times as fast as it does at 20°C. Stomata are minute openings in the epidermal layer of leaves. When there is a high rate of wind activity, transpiration is relatively higher since the moist or humid air around the plant is quickly replaced by less humid air allowing the plant to release even more water into the atmosphere. There are more stomatal openings on the undersurface of a dicot leaf and therefore, more transpiration occurs from the undersurface. 1. So plants lose water in the form of water every day into the atmosphere through transpiration. If so, give reason. The leaves of certain plants exhibit droplets of water along their margins in the morning. 1. Closing of stomata and shedding of leaves reduce transpiration. 1. Transpiration is the process of water evaporating through stoma, or pores, in the foliage of plants. So transpiration rate is higher. 3. Other factors that affect transpiration include: The readings on the capillary tube moves along. Arrange another similar plant and cover it with a bell jar exactly in the same manner as the first one, except that here you also keep a piece of dry cobalt chloride paper by the side of the plant inside the bell jar (B). More the, (e) Cork and Bark of trees are tissues of old woody stems. (a) Intensity of light Narrow leaves:-The leaves may become narrower to reduce surface area. (ii) During the day, the stomata are open to facilitate the inward diffusion of CO2 for photosynthesis. (b) After few hours CaCl2 vials were taken out and weighed again. Loss of water as droplets from the margins of certain leaves is called guttation. The remaining 97–99.5% is lost by transpiration and guttation. (a) Transpiration is the loss of water as water ………… from the ………… parts of the plant. 8. Adaptations in plants to reduce excessive transpiration, Direct loss of water by plants – Guttation and Bleeding. After completing all these processes, transpiration takes place. Sunken stomata: – The stomata may be sunken or covered by hairs. 2. 1. By practising Selina Solutions, students are able to score good marks in Biology. The water vapour condensing on its inner walls. 2. More transpiration occurs from the undersurface of a dicot leaf. These allow diffusion of gases for respiration as well as for photosynthesis. Special pore-bearing structures called hydathodes are present on the margins of the leaf to allow this exudation. Cuticular transpiration: Cuticle is an impermeable covering present on the leaves and stem. Why? 2. (iii) Wind velocity has an effect on transpiration. Given alongside is the diagram of an experimental set-up to demonstrate a certain phenomenon in plants. Transpiration would occur faster. In such cases, the rate of transpiration during midday exceeds the rate of absorption of water by the roots. Give a reason to support your answer. It may retain some of the taste of the foliage, but is clean, potable water that is safe for drinking. 1. Solution:-, (b) Leaf spines and……………………………… Transpiration will be fastest when the day is (a) cool, humid and windy (b) hot, humid and still (c) hot, humid and windy (d) hot, dry and windy Solution:-(d) hot, dry and windy 8. Transpiration is best defined as This builds up a big hydrostatic pressure within the plant and “forces out” the excess water directly from the tips of veins in the leaf. (iv) Voltmeter is an instrument used for measuring the rate of transpiration in green plants. (b) When the rate of transpiration far exceeds the rate of absorption of water by roots, the cells, (c) Plants absorb water continuously through their roots, which is then conducted upwards to, (d) There are more stomatal openings on the lower surface of a dorsiventral leaf. Solution:-, Leaf spines and protection and reduced transpiration, (c) Lenticels and…………………………………. Solution:-. Ganong’s potometer is used to measure the rate of water intake by a plant. Some plants show wilting of their leaves at noon even when the soil is well watered. In your experiments, transpiration was observed by: a. (a) Hydathodes and ……………………………… The. Soil Water Content: Transpiration is reduced if the air outside is humid. Transpiration will be fastest when the day is (a) cool, humid and windy (b) hot, humid and still (c) hot, humid and windy (d) hot, dry and windy. When it is cloudy during the day, the stomata are partially closed and transpiration is reduced. It is the removal of excess of water from the plants because of excess water buildup in the plant. Also on a cloudy day, the air is already dense with the water molecules and can not fill anymore. As to the maximum, Moore et al. Droplets of water may sometimes be seen along the margins of the leaves of a banana plant, growing in wet soil in the mornings. One of the internal factors which affect the rate of transpiration, is, (a) big size of the leaf (b) Colour of the leaf, (c) lower epidermis of leaves (d) hydathodes, 6. Humidity We at BYJU’S have prepared the Selina Solutions Concise Biology Class 10 Chapter 5, wherein questions are answered with detailed explanations. Solution:-. The amount of transpiration from lenticels certainly more than the cuticular transpiration, but very much less than the stomatal transpiration. The purpose of using the monometer in order to measure the pressure exerted by the fluid. Because both surfaces of the leaf is coated with Vaseline. force and in eliminating excess…………. Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers.Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. (b) Explain the process named above in (a). Transpiration will be fastest when the day is (a) cool, humid and windy (b) hot, humid and still (c) hot, humid and windy (d) hot, dry and windy. The cells, therefore, lose turgidity. Most of the transpiration in tall trees occurs through (a) Stomata (b) Lenticels (c) Cuticle (d) Bark. (B) coated on the lower surface. Transpiration in the leaf It causes around 20% of transpiration in plants. Selina Solutions Concise Biology Class 10 Chapter 5 Transpiration, are provided here, so that students can check for the answers whenever they are facing difficulty while answering the questions. What is wilting? The water can be collected at the end of the day, when the transpiration cycle is complete. (a) Openings on the stem through which transpiration occurs. (d) Suggest a suitable control for this experiment. They remain open all the time. List of subtopics covered in Selina Solutions Concise Biology Class 10 Chapter 5 Transpiration, Your email address will not be published. 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