Question

Specialised cells are generally found in the plant leaves which contain outgrowths of epidermal cell wall, made of calcium carbonate or silicon dioxide in a cellulose matrix are called as:

• A. Raphides
• B. Cystolith
• C. Druses
• D. Lithocysts

Hint:

To avoid confusion, remember the relationship: The \textbf{Cystolith} (the stone or mineral deposit) is found inside the \textbf{Lithocyst} (the stone-cell). The question asks for the cell, not the deposit within it.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The question asks to identify the specialized cells in plant leaves that contain specific mineral deposits. These deposits are described as outgrowths of the epidermal cell wall and are composed of calcium carbonate or silicon dioxide within a cellulose matrix. This phenomenon is a form of biomineralization in plants.
Step 3: Detailed Explanation:
Let's analyze the given options:
(A) Raphides: Raphides are needle-shaped crystals, typically made of calcium oxalate, found in the vacuoles of plant cells called idioblasts. [11, 12, 14] They are not outgrowths of the cell wall.
(B) Cystolith: A cystolith is the actual outgrowth or concretion of the epidermal cell wall, composed of calcium carbonate on a cellulose stalk. [1, 5, 7] While the description matches the structure, the question asks for the name of the specialised cell that contains this structure, not the structure itself.
(C) Druses: Druses are star-shaped or globular aggregates of calcium oxalate crystals, also found within plant cells (idioblasts), usually in the vacuole. [11, 15, 16] They are not outgrowths of the cell wall.
(D) Lithocysts: Lithocysts are the specialized, enlarged epidermal cells that contain cystoliths. [2, 8, 17] The question specifically asks for the name of the specialised cells, making this the correct answer. The cystolith is the structure {within} the lithocyst. [1, 10]
Therefore, the specialized cells containing these outgrowths are called Lithocysts.
Step 4: Final Answer:
The correct option is (D) because Lithocysts are the specialized epidermal cells that house the cystoliths, which are the calcium carbonate outgrowths of the cell wall. [2, 3, 8]