7.8 Transport In The Phloem Flashcards
What is a source in a plant?
Leaf tissue
What is a sink in a plant?
New tissues
Roots
Fruit
What is the transport of sugars in plants called?
Translocation
How does sucrose get to the phloem?
It moves by facilitated diffusion and is then actively transported with H+ into the phloem
Describe translocation from when sucrose enters the phloem
Sucrose lowers water potential
Water moves into the phloem from the xylem
At the sinks there is a low hydrostatic pressure
Water moves to sinks carrying sucrose
Companion cells actively transport sugars from phloem to sinks via active transport
What are the adaptations of the companion cell?
Many ribosome to make proteins for facilitated diffusion+ mitochondria
What are the adaptations of the sieve tubes?
Perforated ends allow movement of particles
Thin cytoplasm
No nucleus
How could you prove mass transport with a tree and what may be the disadvantages?
Strip bark
Bottom of tree will die as it gets no sucrose so no respiration
Only shows sucrose is moved in the phloem
How can you prove mass flow with aphid bugs?
They eat phloem tissue
Show sucrose is in insects which mean sucrose is in the phloem
How can you prove mass flow with C-14?
Give C-14 to plants and use a autoradiograph to trace it through the phloem
How can you prove mass transport with respiration inhibitors and what are the disadvantages?
No active transport
Less flow in the phloem
Could just be correlation
