Transpiration Flashcards
What are the four functions of water in the plant?
- transport
- transpiration
- support created through turgor pressure
- photosynthesis
Transpiration is the loss of water by…
Evaporation
What is transpiration?
Evaporation from mesophyll cells followed by diffusion through air spaces and stomata.
In osmosis where does water enter?
The roots.
In a bubble photometer what does the reservoir do?
Allows the apparatus to be reset and record other results.
What must be done with the bubble photometer apparatus?
It must be setup underwater.
Why is there a layer of oil or polythene bag?
To ensure that only the water evaporating and diffusing from the leaves is causing the plant to loose mass.
When light intensity increases?
Rate of transpiration increases.
When temperature increases? Why?
Rate of transpiration is increased. Water molecules have more kinetic energy.
When air movement increases? Why?
Rate of transpiration increases. Maintains steep moisture gradient.
When humidity increases? Why?
Rate of transpiration decreases. Reduces the moisture gradient.
Large surface area? Why?
Increases rate of transpiration. More stomata available.
When does the stomata close?
At night.
Which two important processes requires gases to diffuse into and out of the leaf?
Photosynthesis and respiration.
What are the four environmental conditions that affect the rate of transpiration?
-Light intensity
-Temperature
-Air movement
-Humidity
What happens as the water is evaporated and diffused in terms of the capillary tube?
More water will need to be drawn up the capillary tube to replace what has been lost through transpiration.
If Vaseline is applied to the TOP of a leaf: what happens in terms of water loss and why?
Most stomata are found on the bottom of the leaf meaning that if Vaseline is applied to the top, water loss can still occur and the amount wont be affected.
If Vaseline is applied to the BOTTOM of a leaf: what happens in terms of water loss and why?
There are more stomata found on the bottom of a leaf meaning that, only some water can be lost and the mass of the leaf will only decrease slightly as most stomata are blocked meaning that only a small amount of water will be able to diffuse out of the top surface of the leaf.
