Transpiration And Stomata Flashcards
What is transpiration?
The process by which water vapor is released from plants into the atmosphere
List the four main factors that affect transpiration rate.
- Light Intensity
- Temperature
- Air Flow
- Humidity
How does light intensity affect transpiration rate?
The brighter the light, the greater the transpiration rate; stomata close in darkness.
What effect does temperature have on transpiration?
Warmer temperatures increase the rate of transpiration due to higher energy of water particles.
Explain the relationship between air flow and transpiration.
Better air flow around a leaf increases transpiration; poor air flow leads to high water vapor concentration.
How does humidity influence transpiration?
Drier air increases transpiration; humid air slows it down due to lower concentration gradients.
What is a potometer used for?
To estimate the rate of transpiration by measuring water uptake in plants.
Fill in the blank: Guard cells are adapted to _______ and _______ stomata.
[open] and [close]
Describe the shape and function of guard cells.
They have a kidney shape that opens and closes stomata to facilitate gas exchange.
What happens to guard cells when a plant has lots of water?
They fill with water and become turgid, causing stomata to open.
What occurs to guard cells when the plant is short of water?
They lose water and become flaccid, making stomata close.
Why do guard cells have thin outer walls and thickened inner walls?
To facilitate the opening and closing of stomata.
True or False: Stomata are usually found on the upper surface of leaves.
False; they are usually found on the undersides.
Why are there generally more stomata on the underside of leaves?
The lower surface is shaded and cooler, reducing water loss.
What adaptation allows guard cells to control water loss?
They are sensitive to light and close at night to conserve water.
What is the plural of stoma?
Stomata
How can the distribution of stomata in different leaves be compared?
By peeling the epidermal tissue off leaves and mounting them on microscope slides.
Which plant is likely to have fewer stomata per cm on the underside of its leaves: Aloe vera or primroses?
Aloe vera; it grows in hot, dry areas.
