Class 11 Biology - Chapter Transport in Plants NCERT Solutions | Briefly describe water potential. What a
Briefly describe water potential. What are the factors affecting it?
Water potential quantifies the tendency of water to move from one part to the other during various cellular processes such as diffusion, osmosis, etc. It is denoted by the Greek letter Psi or Ψ and is expressed in Pascals (Pa). The water potential of pure water is always taken as zero at standard temperature and pressure.
Water potential (Ψw) is expressed as the sum of solute potential (Ψs) and pressure potential (Ψp).
Ψw = Ψs + Ψp
When some solute is dissolved in water, the water potential of pure water decreases. This is termed as solute potential (Ψs), which is always negative. For a solution at atmospheric pressure, Ψw = Ψs.
The water potential of pure water or a solution increases on the application of pressure values more than atmospheric pressure. It is termed as pressure potential. It is denoted by Ψp and has a positive value, although a negative pressure potential is present in the xylem. This pressure potential plays a major role in the ascent of water through the stem.
More Questions From Class 11 Biology - Chapter Transport in Plants
- Q:- Explain why xylem transport is unidirectional and phloem transport bi-directional.
- Q:- (a) With the help of well-labelled diagrams, describe the process of plasmolysis in plants, giving appropriate examples.
(b) Explain what will happen to a plant cell if it is kept in a solution having higher water potential. - Q:- What role does root pressure play in water movement in plants?
- Q:- What are the factors affecting the rate of diffusion?
- Q:- Explain pressure flow hypothesis of translocation of sugars in plants.
- Q:- What are porins? What role do they play in diffusion?
- Q:- Explain why pure water has the maximum water potential.Explain why pure water has the maximum water potential.
- Q:- Describe transpiration pull model of water transport in plants. What are the factors influencing transpiration? How is it useful to plants?
- Q:- What causes the opening and closing of guard cells of stomata during transpiration?
- Q:- How is the mycorrhizal association helpful in absorption of water and minerals in plants?
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2 Comment(s) on this Question
your questions are good and answers are also well defined
Very good answer
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