How does bulk flow work in plants?
In general, bulk flow in plant biology typically refers to the movement of water from the soil up through the plant to the leaf tissue through xylem, but can also be applied to the transport of larger solutes (e.g. sucrose) through the phloem.
Do plants use bulk flow?
Animals rely on bulk flow (or other active mechanism) to obtain oxygen and release carbon dioxide (hence breathing, fish sweep water across gills, frog swallowing) Plants rely on diffusion to obtain carbon dioxide and release oxygen (hence leaves are thin)
What is bulk flow in plants?
In general, bulk flow in plant biology typically refers to the movement of water from the soil up through the plant to the leaf tissue through xylem, but can also be applied to the transport of larger solutes (e.g. sucrose) through the phloem.
Do plants have bulk transport?
Long-distance transport of water from roots to leaves occurs by bulk flow, the movement of fluid driven by a pressure difference at opposite ends of a conduit, the xylem vessels or chains of tracheids.
Why do plants use mass flow?
Mass flow is the movement of dissolved nutrients into a plant as the plant absorbs water for transpiration. The process is responsible for most transport of nitrate, sulfate, calcium and magnesium. Diffusion is the movement of nutrients to the root surface in response to a concentration gradient.
How does bulk flow work in trees?
Bulk flow generally occurs in xylem since water from the soil is taken up by the roots and carried throughout the plant through xylem. However, phloem might also be involved in bulk flow as it facilitates the movement of larger sucrose molecules from the leaves to different parts of the plant.
What causes bulk flow in the xylem?
Water and solutes move through xylem vessels and sieve tubes by bulk flow, the movement of a fluid driven by pressure. In phloem, for example, hydrostatic pressure generated at one end of a sieve tube forces sap to the opposite end of the tube.
How bulk flow affects movement of solutes in plants?
Bulk flow moves the whole solution, water plus minerals and any other solutes dissolved in the water. The plant expends none its own metabolic energy to lift xylem sap up to the leaves by bulk flow.
Why is mass flow the best way to transport substances in plants?
Explain why mass flow is the best way to transport substances around the plant. Mass flow is faster and can move large amounts of fluid long distances quickly.
What causes bulk flow in the phloem?
The water absorbed into the sieve tube creates hydrostatic pressure that forces the phloem sap to flow (bulk flow) towards the sink.
What type of pressure is responsible for bulk flow in phloem conduction?
The phloem tissue is the principal sugar conductive tissue in plants. Over 80 years ago, Ernest Münch (1930) proposed the now widely accepted mechanism for phloem transport. According to his theory, the mass flow in the phloem is driven by an osmotically generated pressure gradient.Oct 8, 2013