Question

Theory of root pressure, is not acceptable because

• A. It is not a potent scientific factor informing the water upward
• B. Water continues to rise without root pressure and the later has seldom been observed in gymnosperms
• C. Root pressure can take water up to height 100 ft. only
• D. None of the above

Answer 1

Answer: (B)

Water continues to rise without root pressure and the later has seldom been observed in gymnosperms

Root pressure theory was advanced by Priestley in 1916. According to root pressure theory, water rises upwardly in the xylem due to a positive pressure developed in the root. A root pressure of 1 to 2 atmospheres has been reported in a number of cases. However, root pressure is not universal and is not found in all the seasons. A positive root pressure has not been demonstrated in gymnosperms, even as some of the gymnosperms (Sequoia) are the tallest trees. Water can rise upwards even in the absence of roots.

So, the correct answer is option B.