Plants use capillary action in their roots which are essentially narrow tubes to get water from soil. Based on this information, explain how water moves up the roots of a flower in terms of cohesive and adhesive forces.
keep it short please
1 Answer | Add Yours
Forces holding a liquid together are cohesive forces. The forces of attraction between a liquid and another surface are adhesive forces. Capillary action occurs when one end of a capillary tube is immersed in a liquid. If adhesive forces exceed the cohesive forces, the liquid creeps up along the length of the tube until a compromise is reached between the balance adhesive forces and the weight of the liquid column.
The roots of plants exhibit strong adhesive forces for water, creating a strong adhesive pull for water along the roots.
In addition to the adhesive pull described above, two other major pulls work in tandem in plants, which feed water and dissolved nutrients from roots up to their topmost parts. These are transpiration pull and osmotic pressure.
As transpiration occurs in the leaf, it creates a cohesive pull along water molecules in cell walls which is then transmitted through the xylem down to the roots.
The cellular fluid is denser than water in the soil. This creates an osmotic pull of water through the narrow tubes that are roots.
This combination of forces is sufficient to move water upward against all forces of gravity and transmit them up the stems to the highest parts of plants (leaves, flowers etc.).
Thanks a lot.
We’ve answered 319,673 questions. We can answer yours, too.Ask a question