Trasnport In Plangs Flashcards
What is non ligninfied pits for
Lateral movement of water
Function of casparian strip
Impervious to water
Forces water to pass through plasma membrane
Phosplipid bilayer repels ions/ charged particles etc
Potometer set up
Cut stem under water , prevent air entering xylem, dry leaves
Insert stem underwater, joints must be sealed - obtain continuous flow of water
Using potometer make sure
Not allow bubble to move too far
Place open end in water , so new air bubble introduced
Keep shoot supported
Measure accurately, ensure validity
Practical to measure rate of transpiration
Water lost = water uptake
Movement of bubble in potometer measured
Timing distance travelled,ed by bubble
Repetition to gain replicates
Calculate rate / mean , statistical test eg SD - small SD , more precise
Control variables - LIght, wind , SA of leaves, humidity
Other part of plant that water can diffuse out of
Epidermis
How is guard cell adapted
Thick inner wall + thinner outer wall, able to change shape / bend
Chloroplast to produced ATP
How does water move up
Evaporation at top xylem , creates tension in xylem - transpiration pull
Cohesive + adhesives - capillary action
Chain pulled up by tension
Transpiration stream
Movement of water from up xylem vessels roots to leaves
Why plant need transport system
Small SA:V ratio, discussion distance too long
