Investigating Transpiration Flashcards
(16 cards)
What equipment is used to investigate transpiration?
A potometer.
Why is the leafy shoot cut under water?
To prevent air from entering the xylem vessels.
What holds the leafy shoot in place in the potometer?
A stopper with a hole for the shoot.
How is the potometer filled?
It is completely filled with water before attaching the shoot.
How is the air bubble introduced into the capillary tube?
By removing the capillary tube from water briefly, then re-immersing it.
How is the rate of transpiration measured?
By measuring the distance the air bubble moves per unit time.
Why is the tap on the reservoir closed during the experiment?
To prevent water from refilling the capillary tube and interfering with measurements.
Why is the end of the capillary tube re-immersed in water?
To reset the air bubble position for repeated trials.
How does light intensity affect transpiration?
Increased light intensity increases transpiration, as stomata open wider to allow gas exchange.
How does temperature affect transpiration?
Higher temperature increases transpiration, as it causes water to evaporate more quickly from the leaf surface.
How does humidity affect transpiration?
Increased humidity decreases transpiration, as the concentration gradient between the leaf and surrounding air is smaller.
How does wind affect transpiration?
Wind increases transpiration, as it removes water vapour around the leaf, maintaining a strong concentration gradient.
How does soil water availability affect transpiration?
Low soil water availability reduces transpiration, as the plant has less water to transport through its xylem.
How do stomata affect transpiration?
Stomata control water loss; their opening increases transpiration, while their closing reduces it.
How does leaf surface area affect transpiration?
Larger leaf surface areas increase transpiration, as more surface is available for water evaporation.
How does the presence of waxy cuticle affect transpiration?
A thicker waxy cuticle reduces transpiration, as it reduces water loss from the leaf surface.
