Q.26 Match List I with List II:
| List I | List II |
|---|---|
| (A) Phyllotaxy | (I) H.H. Dixon and J. Joly |
| (B) Cohesion theory | (II) E. Munch |
| (C) Pressure flow hypothesis | (III) Leonardo Fibonacci |
| (D) Quiescent center | (IV) F.A.L. Clowes |
Answer: (2) (A)-(III), (B)-(I), (C)-(II), (D)-(IV)
Phyllotaxy links to Leonardo Fibonacci for spiral patterns, cohesion theory to H.H. Dixon and J. Joly, pressure flow hypothesis to E. Munch, and quiescent center to F.A.L. Clowes, confirming option (2).
Match Explanations
(A) Phyllotaxy – (III) Leonardo Fibonacci
Phyllotaxy describes leaf arrangements on stems, often following Fibonacci sequence ratios (e.g., 3/5, 5/8) for optimal light exposure, noted in his 1202 Liber Abaci rabbit problem and observed in spirals.
(B) Cohesion Theory – (I) H.H. Dixon and J. Joly
Dixon and Joly (1894) proposed cohesion-tension theory for xylem sap ascent, where transpiration pull creates tension, countered by water cohesion/adhesion in vessels.
(C) Pressure Flow Hypothesis – (II) E. Munch
Ernst Munch (1930) described phloem transport as osmosis-driven pressure flow: high turgor at source (loading sugars) pushes sap to sink (unloading).
(D) Quiescent Center – (IV) F.A.L. Clowes
F.A.L. Clowes (1950s) identified the quiescent center in root apical meristem as slowly dividing cells organizing surrounding rapid divisions.
Option Verification
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(1) Wrong: Phyllotaxy not Fibonacci; cohesion not III.
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(2) Correct: Matches all pairs above.
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(3) Wrong: Phyllotaxy not IV; cohesion not II.
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(4) Wrong: Phyllotaxy not I; quiescent not III.
Phyllotaxy cohesion theory pressure flow quiescent center matching reveals key plant physiology discoveries by Fibonacci, Dixon-Joly, Munch, and Clowes, essential for stem arrangement, water ascent, phloem transport, and root meristem.
Discoveries Breakdown
These concepts underpin plant growth: Fibonacci’s numbers optimize phyllotaxy spirals; Dixon-Joly’s cohesion explains 100m+ sap rise; Munch’s pressure flow drives 1 m/h phloem speeds; Clowes’ quiescent center maintains root tips.
| List I | Scientist | Contribution |
|---|---|---|
| Phyllotaxy | Leonardo Fibonacci | Spiral leaf patterns |
| Cohesion Theory | H.H. Dixon & J. Joly | Xylem transpiration pull |
| Pressure Flow Hypothesis | E. Munch | Phloem osmosis flow |
| Quiescent Center | F.A.L. Clowes | Root meristem organization |
Exam Strategy
In CUET PG Botany or GATE Life Sciences, memorize pairings—Fibonacci (math-botany link), Dixon-Joly (xylem), Munch (phloem), Clowes (meristem). Useful for Rajasthan’s crop physiology studies.
