How pressure flows explain translocation?
Explain the pressure-flow hypothesis of the translocation of sugars in plants. According to the pressure-flow hypothesis, food is prepared in the plant leaves in the form of glucose. Before moving into the source cells present in the phloem, the prepared food is converted into sucrose.
Is translocation positive pressure?
While movement of water and minerals through the xylem is driven by negative pressures (tension) most of the time, movement through the phloem is driven by positive hydrostatic pressure. This process is termed translocation, and is accomplished by a process called phloem loading and unloading.
What are the steps of translocation in plants?
Translocation is the movement of materials in plants from the leaves to other parts of the plant. Nutrients, mainly sugars, are created in the leaves during photosynthesis. These are then transported throughout the plant through phloem, which are a long series of connected cells.
What is the first step in the pressure flow mechanism of translocation?
In the first step of this model, sugar (mainly sucrose) is actively transported from source cells into the sieve tubes of the phloem. The addition of sucrose into the sieve tubes increases the concentration of this solute, causing water to flow into the sieve tubes by osmosis.
How the pressure flow hypothesis accounts for translocation in the phloem?
The Pressure-Flow Hypothesis It proposes that water containing food molecules flows under pressure through the phloem. The pressure is created by the difference in water concentration of the solution in the phloem and the relatively pure water in the nearby xylem ducts.
How does the pressure flow hypothesis explain the function of phloem?
The pressure flow hypothesis helps explain how dissolved sugars move from sugar sources to sugar sinks. When sinks need sugar, the pressure difference between the source and sink causes dissolved sugars to move to the area of need. Excess sugars can be stored in areas such as roots to be used later.
Which process is an example of translocation?
Translocation is a biological process that involves the movement of water and other soluble nutrients through the xylem and phloem from one part of the plant to another part of the plant. For example transportation of sucrose and amino acid, up and down the plant.
Why is translocation an active process?
The glucose that is produced inside the chloroplast of the leaves is actively pumped into the sieve tube of the phloem for transportation. Again when the glucose reaches the tissue it is removed from sieve tube to the tissue by active transport. For this reason translocation is considered to be an active process.
What is root pressure in plants?
root pressure, in plants, force that helps to drive fluids upward into the water-conducting vessels (xylem). It is primarily generated by osmotic pressure in the cells of the roots and can be demonstrated by exudation of fluid when the stem is cut off just aboveground.
Which of the following is the correct sequence of events in the pressure flow mechanism of phloem transport?
Which of the following is the correct sequence of events in the pressure-flow mechanism of phloem transport? Sugar is loaded into phloem, water moves from xylem to phloem by osmosis, fluid pressure increases inside the phloem, phloem sap is squeezed to new locations in the plant, and sugar is removed from the phloem.