Pressure Flow Hypothesis
High turgor pressure near sources causes phloem sap to flow here.
What are sinks?
Osmoconformers spend a lot of energy to prevent toxic concentrations of this waste product.
What is urea?
What is fish have higher salt concentrations than the freshwater? (fish > freshwater)
Tissue where the sugar exits phloem
What is a sink?
The movement of water down its concentration gradient across a semipermeable membrane.
What is osmosis?
During this step, water in phloem sap moves down the pressure gradient passively and sugars are actively carried via bulk flow.
What is phloem loading?
Name the two strategies for living in the ocean.
Freshwater produce _______ urine.
What is lots of dilute urine?
In young growing leaves, phloem unloading occurs by this process and is rapidly used up in cells of these leaves.
What is simple diffusion?
These organisms actively regulate their internal water and electrolyte levels, independent of the surrounding environment.
What are osmoregulators?
These are found in the membranes of companion cells creating a strong electrochemical gradient that favors a flow of protons into companion cells.
What are proton pumps?
________ bony fishes and cartilaginous fishes experience severe osmotic stress.
Describe the flow of water in freshwater fish.
What is turgor pressure?
Organisms that keep their internal fluids similar to their ambient conditions.
What are osmoconformers?
In root cells, a large vacuole stores sucrose, and is surrounded by this membrane.
What is the tonoplast?
This nitrogenous waste product is highly toxic.
What is ammonia?
Freshwater fish lose salt across their gill epithelium by what process?
Phloem unload sugars into what parts of a sugar beet?
What are growing leaves and roots?
The concentration of solutes in solution.
What is osmolarity?
This cotransporter moves sucrose into the vacuole against its concentration gradient.
What is the proton-sucrose antiporter?
This form of nitrogenous waste is not soluble in water and is produced by birds and reptiles.
What is Uric Acid?
The type of transport required to reabsorb salt at the gills.
active
Turgor pressure near the source is ___.
What is high?
When water and solute concentrations differ from their set points, organisms experience this.
What is osmotic stress?