Question

Pressure potential is usually positive but negative in case of
A. Xylem vessels
B. Plasmolysed cell
C. Both A and B
D. Turgid cell

Answer 1

Hint:- The minerals and ions are transported through the water-conducting tissue of the plants that is xylem. It helps in the transportation of minerals and ions absorbed by the roots. It conducts the water and minerals to the stem and leaves of the plant.

Complete step-by-step solution:-
- The pressure potential is described as a physical pressure that is exerted by cell membranes on the water molecules. The pressure potential increases as the pressure increases. It is a component of water potential.
- Pressure potential is usually positive, but it is negative in the case of xylem vessels. It is also known as wall pressure or turgor pressure.
The pressure potential is usually positive in a turgid plant cell. It is negative in xylem tissues and is a potential pressure in a transpiring plant.
Thus, the correct option is (A). Xylem vessels.

Additional information:- The water potential is described as the tendency of water to move from one part to different parts of the plant body. The movement of water can take place during several cellular processes such as osmosis, diffusion, and other processes.
The water potential is denoted by the Greek letter Psi or . It is expressed in pascals (Pa).
The water potential of pure water is zero always at standard temperature and pressure.
The water potential is expressed in an equation as a sum of solute potential and pressure potential.

Note:- There are two primary components found in plants are as following:
- Xylem is water-conducting tissue, and it helps in the transportation of water and minerals from roots to stem and leaves.
- Phloem is food conducting tissue of plants, and it helps in the transportation of food. The leaves prepare the food and are transported to the growing tips, stem, and fruits.