Mass Flow 2

Question 1

How is sucrose actively loaded into companion cells at source?

Answer 1

Co-transport with hydrogen ions

Question 2

Evidence against mass flow hypothesis

Answer 2

Sugar travels to many different sinks and does not move faster to the one with highest water potential which it should according to mass flow hypothesis.

Question 3

Evidence for mass flow hypothesis

Answer 3

Preventing ATP production stops translocation but not water movement
Sucrose concentration higher in leaves than roots

Question 4

What are 2 types of experiment that can provide evidence for mass flow?

Answer 4

Ringing experiments
Tracing experiments