Question

In plants, atmospheric pressure can rise water to the maximum of

• A. 40 ft
• B. 38 ft
• C. 34 ft
• D. 30 ft

Answer 1

Answer: (C)

34 ft

'Atmospheric pressure theory' was advanced to explain ascent of sap in plants. When water escapes by transpiration from the surface of the leaves, there will be the less amount of water within the plant body. So, the atmospheric pressure supports the water to be lifted only to a height of 34 feet; but there are plants, which are taller than this and still there is transport of water. Hence, it can be concluded that atmospheric pressure could not be the force for ascent of sap.