Question

Match the following: 

List-I (Name of the Stele)	List-II (Character)
A. Protostele	I. Dissected siphonostele with overlapping leaf gaps
B. Siphonostele	II. Siphonostele with scattered leaf gaps
C. Solenostele	III. Medullated protostele
D. Dictyostele	IV. Xylem surrounded by phloem

• A. A-III, B-IV, C-II, D-I
• B. A-I, B-III, C-II, D-IV
• C. A-IV, B-III, C-I, D-II
• D. A-IV, B-III, C-II, D-I

Hint:

Protostele = Xylem surrounded by phloem; Siphonostele = Pith present; Solenostele = Non-overlapping leaf gaps; Dictyostele = Overlapping leaf gaps.

Answer 1

The Correct Option is D

Concept: Stele refers to the central vascular cylinder of roots and stems. During the evolution of vascular plants, different stelar organizations developed, each characterized by a unique arrangement of xylem, phloem and pith. Understanding these stelar types is important in plant anatomy and pteridophyte evolution.

Step 1: Identify Protostele. Protostele is the simplest and most primitive stele. It consists of a solid central core of xylem completely surrounded by phloem. Thus, \[ A \rightarrow IV \]

Step 2: Identify Siphonostele. A siphonostele is considered a medullated protostele because it contains a central pith. Thus, \[ B \rightarrow III \]

Step 3: Identify Solenostele. A solenostele is a siphonostele possessing leaf gaps that do not overlap. Hence it is described as a siphonostele with scattered leaf gaps. Thus, \[ C \rightarrow II \]

Step 4: Identify Dictyostele. Dictyostele develops when numerous leaf gaps overlap. As a result, the vascular cylinder becomes dissected into many separate strands. Thus, \[ D \rightarrow I \]

Step 5: Final matching. \[ A-IV,\quad B-III,\quad C-II,\quad D-I \] Hence option (D) is correct.