4.7

Question 1

symplast pathway?

Answer 1

thru plasmodesmata + cytoplasm

Question 2

apoplast pathway?

Answer 2

thru cell walls - but once reach casparian strip = symplast

Question 3

is symplast or apoplast faster

Answer 3

apoplast, symplast has organelles - block flow

Question 4

cohesion-tension model?

Answer 4

• water uptake in roots by O - water moves across root hair cells by O - reaches xylem
• at top water diffuses ou stomata by transportation, this causes water to move along spongy mesophyll cells - pulls water up xylem due to cohesive forces

Question 5

factors affecting transpiration, 5

Answer 5

humidity, temp, light, air movement, water availability = in soil

Question 6

what does translocation require

Answer 6

ATP

Question 7

how does translocation work?

Answer 7

1. glucose converted into sucrose - sucrose offloaded into CC of phloem - moves into STE thru plasmodesmata by diffusion - lowers water potential so water moves in from xylem
2. increased HP so sucrose moves down plpoem from source to sink - moves out phloem by facilitated diffusion

Question 8

mass flow hypothesis +, -

Answer 8

+ Accounts for one-way flow in individual tubes
- Can’t explain two-way flow in the same tube