The lower the RH, the less moist the atmosphere and thus, the greater the driving force for transpiration. Figure 5.17: Transpiration vs humidity. - … The cuticle, being made of wax, has a limiting effect on the transpiration rate by hampering the diffusion of water vapor to the outside atmosphere. Thus higher the wind speed, greater is the rate of evaporation. Transpiration occurs because plants take in more water than they actually need at a given time. Factors that affect the rate of transpiration also affect water uptake by the plant. Due to this, air has a lot of capacity to hold water and thus the rate of transpiration increases. 3. If there is wind, it moves this water vapor laden air away while dry air takes its place. Rate of transpiration is more when:- (a) atmosphere is dry, (b) temperature is high, (c) humidity is high, (d) atmosphere is high and temperature is high. The rate of transpiration is more when (a) atmosphere is dry (b) temperature is high (c) humidity is high (d) atmosphere is dry and temperature is high. The rate of transpiration depends upon the difference in the vapour pressure between the internal atmosphere of the leaf and air outside the leaf. If the rate of transpiration increases, the rate of absorption of water by the root increases too. Similarly, high temperatures evaporate the water at a much higher rate thus again increasing the rate of transpiration. Solution 1: (a) Open stomata, dry atmosphere and moist soil Question 2: With decrease in atmospheric pressure, the rate of transpiration will (a) increase (b) decrease rapidly (c) decrease slowly (d) remain the same Solution 2: (a) increase Question 3: The rate of transpiration is more when (a) atmosphere is dry (b) … Transpiration is very important for maintaining moisture conditions in the environment. In strong light, the rate of transpiration is more because stomata are wide open. Any reduction in water in the atmosphere creates a gradient for water to move from the leaf to the atmosphere. Sunken stomata, as in adelfa or Nerium oleander, also lessen the rate of transpiration by sheltering the boundary layer from wind movement. Transpiration vs humidity. How Do Plants Lose Water? Since relative humidity is the actual amount of water vapours in the atmosphere at any given time, the rate of transpiration is mainly dependent on it. However, if the atmosphere is dry, there will be a steep water concentration gradient between the humid inside of the stomata and the outside air and the rate of transpiration will therefore be fast. Likewise, the presence of dry epidermal … Transpiration is the process by which water contained in plant tissues is lost to the atmosphere by the process of evaporation. In dim light or on a cloudy day the stomata are partially closed reducing the rate of transpiration. When RH is high, the atmosphere contains more moisture, reducing the driving force for transpiration. 4. Solution:-(b) temperature is high. Function of Transpiration. However, if the atmosphere is dry, there will be a steep water concentration gradient between the humid inside of the stomata and the outside air and the rate of transpiration will therefore be fast. As much as 10 percent of the moisture in the Earth’s atmosphere is from transpiration of water by plants. One of the internal factors which affect the rate of transpiration, is (a) big size of the leaf (b) Colour of the leaf (c) sunken stomata … Dry atmosphere means lack of moisture content in the air. 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