MHT CET 202622 AprilEvening Shift
- Exam
- MHT CET
- Year
- 2026
- Date
- 22 April
- Shift
- Evening Shift
- Subject
- Biology
- Chapter
- Transport in Plants
MHT CET 2026 · 22 April · Evening Shift · Biology · Transport in Plants
Given below are two statements regarding the root pressure theory...
Given below are two statements regarding the root pressure theory of translocation of water in plants.
Statement (I): Under normal conditions, the sap in the xylem cells shows negative hydrostatic pressure.
Statement (II): It also shows high osmotic pressure.
In light of the above statements, choose the most appropriate answer from the options given below.
Statement (I): Under normal conditions, the sap in the xylem cells shows negative hydrostatic pressure.
Statement (II): It also shows high osmotic pressure.
In light of the above statements, choose the most appropriate answer from the options given below.
Options
- ABoth Statement (I) and Statement (II) are correct.
- BBoth Statement (I) and Statement (II) are incorrect.
- CStatement (I) is correct but Statement (II) is incorrect.
- DStatement (I) is incorrect but Statement (II) is correct.
Correct answer
C. Statement (I) is correct but Statement (II) is incorrect.
Step-by-step solution
Regarding the root pressure theory of water translocation, there are several objections based on observations of plants under normal conditions:
First, under normal conditions (when transpiration is occurring), the sap in the xylem cells is under tension due to transpiration pull. This means it exhibits a negative hydrostatic pressure rather than the positive pressure proposed by the root pressure theory. Therefore, Statement (I) is correct.
Second, the xylem sap consists primarily of water with a very dilute concentration of dissolved minerals. Because the solute concentration is very low, the xylem sap exhibits a low osmotic pressure, not a high osmotic pressure. Therefore, Statement (II) is incorrect.
Hence, Statement (I) is correct but Statement (II) is incorrect.
Answer: Statement (I) is correct but Statement (II) is incorrect.
First, under normal conditions (when transpiration is occurring), the sap in the xylem cells is under tension due to transpiration pull. This means it exhibits a negative hydrostatic pressure rather than the positive pressure proposed by the root pressure theory. Therefore, Statement (I) is correct.
Second, the xylem sap consists primarily of water with a very dilute concentration of dissolved minerals. Because the solute concentration is very low, the xylem sap exhibits a low osmotic pressure, not a high osmotic pressure. Therefore, Statement (II) is incorrect.
Hence, Statement (I) is correct but Statement (II) is incorrect.
Answer: Statement (I) is correct but Statement (II) is incorrect.