Match List I with List II
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Choose the correct answer from the options given below:
Show Hint
To solve this quickly, associate these key terms:
- J.C. Bose \(\rightarrow\) Pulsation theory (B - I).
- Dixon and Jolly \(\rightarrow\) Transpiration pull (D - III).
Matching these two pairs allows you to identify the correct option immediately.
Step 1: Understanding the Concept:
The ascent of sap refers to the upward movement of water and dissolved minerals from the roots to the leaves against gravity.
Historically, several physical and vital theories were proposed to explain this phenomenon. Step 2: Detailed Explanation:
Let us match each theory with its respective author:
- A. Root pressure theory: Proposed by Joseph Priestley in 17 He suggested that active absorption by root cells generates a hydrostatic pressure (root pressure) that pushes water upward through the xylem vessels.
Thus, A matches with II.
- B. Pulsation theory: Proposed by the Indian physicist Sir J.C. Bose in 192 He suggested that the innermost cortical cells of the root undergo rhythmic, pulsatory movements (similar to a heart beat) that pump water upward.
Thus, B matches with I.
- C. Relay pump hypothesis: Proposed by Godlewski in 188 He suggested that the rhythmic change in the osmotic pressure of xylem parenchyma and medullary ray cells acts as a pump to lift water.
Thus, C matches with IV.
- D. Transpiration pull theory: Proposed by Dixon and Jolly in 189 This physical theory (the cohesion-tension theory) states that transpiration from leaves creates a continuous tension (pull) that draws water upward, aided by the cohesive and adhesive properties of water molecules. This is the globally accepted mechanism.
Thus, D matches with III.
The correct matching sequence is: A-II, B-I, C-IV, D-III. Step 3: Final Answer:
The correct option is (B).
