Ch 38 - Plant Transport

Question 1

Water Transport

Answer 1

Rises through xylem

Some exists through stomata in leaves

Question 1

Short distance transport

Answer 1

Water diffusion through cell membranes

Ions move through membrane bound active transporters

Question 2

Long distance transport

Answer 2

“Pulling”
Transpiration: evaporation of thin films in stomata
Cohesion and Adhesion

Question 2

Water Potential

Answer 2

Osmosis: diffusion across semi-permeable
Turgid: high water potential, low osmotic concentration
Plasmolysis: low water potential, high osmotic concentration

Question 3

Aquaporins

Answer 3

Water channels

Speed up osmosis

Question 3

Water potential

Answer 3

Regulates movement of water through plant
Moves from soil to root only if soil’s potential is greater
Evaporation=negative potential

Question 4

Absorption

Answer 4

Root hairs: absorb most water, turgid
Takes energy to accumulate ions
Then transported via xylem

Question 4

Xylem Transport

Answer 4

Root pressure caused by ions in roots
Causes water to move up xylem without transpiration
Guttation (dew) = loss of water when root pressure is high
Mostly driven by transpiration
Adhesion of water molecules up columns
Use thin tracheids and vessels

Question 5

Rate of Transpiration

Answer 5

90% of water will be lost to atmosphere
Stomata can close to help this
But must open for CO2 transfer
Guard cells open and close stomata

Question 5

Water Stress Response - Drought

Answer 5

dormancy
loss of leaves
reducing number of stomata
stomata in pits on leaf surface

Question 6

Water Stress Responses

Answer 6

Aerenchyma: to live in fresh water, loos parenchymal tissue with large air pores
Pneumatophores: for salt water, air filled roots above mud, secrete salt

Question 6

Phloem Transport

Answer 6

Transports carbs
called Translocation provides building blocks for growing plant
Fluid translocated is called sap

Question 7

Absorption

Answer 7

Root hairs: absorb most water, turgid
Takes energy to accumulate ions
Then transported via xylem

Question 7

Absorption

Answer 7

Root hairs: absorb most water, turgid
Takes energy to accumulate ions
Then transported via xylem

Question 8

Xylem Transport

Answer 8

Root pressure caused by ions in roots
Causes water to move up xylem without transpiration
Guttation (dew) = loss of water when root pressure is high
Mostly driven by transpiration
Adhesion of water molecules up columns
Use thin tracheids and vessels

Question 8

Xylem Transport

Answer 8

Root pressure caused by ions in roots
Causes water to move up xylem without transpiration
Guttation (dew) = loss of water when root pressure is high
Mostly driven by transpiration
Adhesion of water molecules up columns
Use thin tracheids and vessels

Question 9

Rate of Transpiration

Answer 9

90% of water will be lost to atmosphere
Stomata can close to help this
But must open for CO2 transfer
Guard cells open and close stomata

Question 10

Water Stress Response - Drought

Answer 10

dormancy
loss of leaves
reducing number of stomata
stomata in pits on leaf surface

Question 11

Water Stress Responses

Answer 11

Aerenchyma: to live in fresh water, loos parenchymal tissue with large air pores
Pneumatophores: for salt water, air filled roots above mud, secrete salt

Question 12

Phloem Transport

Answer 12

Transports carbs
called Translocation provides building blocks for growing plant
Fluid translocated is called sap

Question 13

Pressure Flow Theory

Answer 13

Model to describe moving carbs thru phloem
Carbs flow from source (photosynthetic tissue)
Carbs released into sink (growing parts)