factors affecting transpiration

Created by

Bupe katebe

Cards (12)

state the precautions that should be taken when using a potometre
PRECAUTION- don’t allow air to enter cut shoot
EXPLANATION- prevents airlock/ensures continuous transpiration stream/pull
PRECAUTION- keep (named abiotic factor) constant
EXPLANATION- as it affects the rate of transpiration
PRECAUTION- keep screw clip closed
EXPLANATION- to prevent entry of water while measuring
what is transpiration a natural consequence of?
gaseous exchange
carbon dioxide moving into the leaf and oxygen moving out
what is the continuous column of water developed in transpiration called?
transpiration stream
how does water evaporate from leaves?
leaves out the spongy mesophyll
as water diffuses from one cell to another, WP in the previous cell is decreased so water continues to diffuse through from cell to cell
what is adhesion and cohesion in a plant
cohesion- water forming hydrogen bonds with each other
adhesion- forming hydrogen bonds with carbohydrates in the walls of xylem vessels
what is capillary action?
the combined effect of water exhibiting cohesion and adhesion- water rises up a narrow tube against gravity
what is the theory relating to the continuous transpiration pull up a xylem?
cohesion-tension theory
true or false? the inner wall of a guard cell is less flexible than the outer wall
TRUE
what happens to guard cells in lots and little water?
solutes pumped in by active transport, increases turgor (lots)
turgor loss is triggered to conserve water (little)
how does temperature affect the rate of transpiration?
water molecules have more kinetic energy to move out
increase in temperature decreases the humidity and water potential of the external air
how does light affect transpiration?
in low light levels stomata close
why is using a potometer only an estimate of the rate of transpiration in a plant?
water can be used for photosynthesis
water can be used to maintain turgor pressure