Question

What is a mass or bulk flow system?

Answer 1

Circulation of blood, water transport in xylem vessels and plant phloem tubes are the examples of mass or bulk flow systems.

Complete answer:
First let know about the role of mass or bulk flow systems in different fields to answer this question. The motion of material matter is mass flow, also known as mass transfer and bulk flow. Mass flow happens in open systems in physics and is also measured as arising while moving over a certain boundary defined by a flow rate and its cross-sectional area. In engineering and biology, fluids can flow in a tube or vessel of a certain diameter. Often known as a bulk flow that is a bulk movement of particles of matter in a defined form of flow.
The water will then flow up into the region of less pressure via the xylem. Mass flow or bulk flow is the movement down a pressure gradient ( a pressure gradient in plants is observed due to variations in solute concentration) or temperature gradient of substances in bulk or in masses. Xylem and phloem in plants play a similar role as veins and arteries in animals. In the circulatory system, from areas of high pressure to areas of low pressure, blood flows via the arteries and veins. In order to move materials to different locations, plants often rely on bulk flow. Water evaporates in a phase called transpiration in the xylem of the leaves, which causes less strain in the xylem.

Note: In plants, bulk flow is a faster mechanism than osmosis or diffusion, both of which require passive material transport from an environment of high to low pressure. Yet diffusion is an issue for tall plants because this process moves materials over short distances. Bulk flow will drive water all the way to its leaves from a plant's roots.