vocabulary
_________: 葉肉細胞
mesophyll cells
Is humidity an factor affecting the rate of transpiration?
Yes, it is
If the humidity increases, will the rate of transpiration increase?
No, it won't.
________ :濃度梯度
concentration gradient
What are the environmental factors affecting the rate of transpiration?
light intensity, temperature, humidity and wind
If the air is still, will there is a lower rate of transpiration?
Yes, it will.
_________: the evaporation of water from a plant’s leaves, stem or flowers
transpiration
By affecting evaporation, gas diffusion and the size of stomatal opening
What is the definition of humidity?
humidity is a measure of the degree that the atmosphere is saturated with water vapor.
___________:a tiny hole in a plant’s leaf or stem
stomata
Why does a rise in light intensity cause a higher rate of transpiration?
Because a rise in light intensity can cause the stomata to open widely. As a result, water vapor can diffuse more rapidly out of the stomata.
And a rise in light intensity can lead to higher leaf temperature and cause faster water evaporation.
Why does the lower humidity increase the rate of transpiration?
Because it can increase the concentration gradient of water vapor between the air spaces in the leaf and the atmosphere. As a result, the plant will lose water faster.
___________:movement of gas from an area of high concentration to low concentration
gas diffusion
Why does an increase in temperature lead to a higher transpiration rate?
It is because the rate of water evaporation from the mesophyll cells increases. Another reason is that air can hold more water vapor, which causes faster water vapor diffusion out of the leaf.
Why does the windy weather result in a higher rate of transpiration?
Because water vapor coming out of the leaf is blown away rapidly. This maintains a high concentration gradient of water vapor and water vapor diffuses rapidly out of the leaf.