Question

A root hair cell under ordinary conditions have a water potential in the range of

• A. 1 to 4 atm
• B. -1 to - 4 atm
• C. 1 to 2 atm
• D. -1 to 2 atm

Answer 1

The correct option is B -1 to - 4 atm

Water potential depends on the number of molecules of water in the system. More the number of water molecules more the water potential. Water potential of pure water is maximum and is zero. Water potential of all solutions is hence negative.

Water always moves from a region or solution of higher water potential to a region or solution of lower water potential. Hence, water potential of root cells cannot be more than zero or have positive value. The water potential of root cells should be less than zero, i.e., have a negative value.

So, the correct answer is '-1 to - 4 atm'