Homework SourseTwo identical plants are taking water up into their roots at
Two identical plants are taking water up into their roots at the same rate. One plant is growing in soil watered with pristine (pure) rain water, the other is growing in brackish water containing ~50 mM NaCl (s = -0.244 MPa). How is it that both plants can take up water at the same rate?
They cannot take up water at the same rate, the one growing in brackish water has to be slower
The solutes in the surrounding water have no impact on events in the root
The plant in brackish water reduces the solute potential in the xylem (makes it more negative) to compensate
The plant in brackish water increases the solute potential in the xylem (makes it less negative) to compensate
The plant in brackish water reduces the casparian strip to allow more water to enter.
| They cannot take up water at the same rate, the one growing in brackish water has to be slower | ||
| The solutes in the surrounding water have no impact on events in the root | ||
| The plant in brackish water reduces the solute potential in the xylem (makes it more negative) to compensate | ||
| The plant in brackish water increases the solute potential in the xylem (makes it less negative) to compensate | ||
| The plant in brackish water reduces the casparian strip to allow more water to enter. |
Solution
The plant in brackish water reduces the solute potential in the xylem as the solute potential decreases with increasing solute concentration. A decrease in solute potential causes decrease in total water potential.Water always moves from the system with a higher water potential to the system with lower water potential. Hence the option at third number is correct.
