Definition check — In plant biotechnology, “protoplasts” are cells that are devoid of which structural component?

Introduction / Context:
Protoplasts are plant, fungal, or algal cells whose cell walls have been removed, leaving the plasma membrane intact. They are foundational for protoplast fusion, direct DNA uptake, and cellular studies requiring wall-less cells.

Given Data / Assumptions:

• Wall removal is typically achieved using cellulases, pectinases, and hemicellulases.
• Osmotic stabilizers prevent lysis once the rigid wall is gone.
• Viable protoplasts retain functional plasma membranes.

Concept / Approach:
Differentiate between the cell wall (external, polysaccharide-rich) and the cell membrane (phospholipid bilayer). A protoplast must have an intact membrane to be living; therefore it cannot be missing the membrane.

Step-by-Step Solution:

Verification / Alternative check:
Microscopy shows spherical morphology and plasmolysis sensitivity characteristic of wall-less cells.

Why Other Options Are Wrong:

Common Pitfalls:
Using insufficient osmotic support leads to protoplast bursting; ensure isotonic conditions.

Final Answer:
Cell wall (removed enzymatically or chemically).