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Questions
Explain capillarity theory.
Answer the following question.
Explain capillarity theory of water translocation.
Solution
Capillarity theory of water translocation:
- This theory was put forth by Boehm in (1863).
- According to this theory, physical forces and dead cells are responsible for the ascent of sap. For e.g. Wick dipped in an oil lamp, shows capillarity due to which oil is raised upwards. The conduction of water in a straw dipped in water is raised to a certain height because of capillarity. The height to which water is raised depends on the diameter of the straw.
- Capillarity is because of surface tension, and forces of cohesion (attraction between like molecules) and adhesion (attraction between unlike molecules).
- Xylem vessel/ tracheid with its lumen can be compared with straw.
- Water column exists because of combined cohesive and adhesive forces of water and xylem wall, due to capillarity.
- Due to capillarity, water is raised or conducted upwards against gravity, to few centimeters only.
RELATED QUESTIONS
Name the conducting tissue in plants which is made of dead cells.
What is transpirational pull?
Very short answer question.
In which conditions transpiration pull will be affected?
Answer the following question.
Discuss theories of water translocation.
Answer the following question.
Define and or explain the term:
Ascent of sap
Long answer question.
Explain cohesion theory for translocation of water.
Find the physical process NOT involved in absorption of water in plants.
Attraction of water molecules to polar surface is known as ______.
In vascular plants, growth takes place due to
How is transpirational pull caused?
