How is the rate of transpiration affected by decreasing humidity and by decreasing light intensity? Decreasing humidity Decreasing light intensity (a). Decreases Decreases (b). Increases Decreases (c). Increases Increases (d). Decreases Increases
How is the rate of transpiration affected by decreasing humidity and by decreasing light intensity? Decreasing humidity Decreasing light intensity (a). Decreases Decreases (b). Increases Decreases (c). Increases Increases (d). Decreases Increases Correct Answer (b)
The correct answer is (b)
Transpiration:
- Transpiration is a process of removal of water from the plant's surface area to the atmosphere.
- Although transpiration occurs through all parts of the plant, the stomata (Small openings on the leaves) contributes the most.
Humidity and its effect on the rate of transpiration:
- Humidity is the amount of moisture content in the air.
- When humidity increases, the amount of water/moisture content of the air increases, thus the air becomes more saturated with water.
- As the air is already saturated with water and there remains less space for extra water molecules, the rate of transpiration falls.
- Similarly, when the humidity decreases, the rate of transpiration increases.
The intensity of light and its effect on the rate of transpiration:
- The intensity of light is a measure of the amount of light that is falling on a surface.
- The more is the intensity, the higher is the illumination of the surface.
- Light is a made up of photons. Photons have energy with them, which mainly gets converted into heat energy.
- This heat energy raises the temperature of the atmosphere.
- When the temperature increases, the moisture carrying capacity of the air increases.
- When the moisture carrying capacity of the air increases, there is more space left for new water molecules to accommodate in the air.
- This increases the rate of transpiration through plants.
- Similarly, when the light intensity decreases, the rate of transpiration also decreases.
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Feb 20, 2025