Question

Cell wall is the secretion product of

• A. Plasmalemma
• B. Tonoplast
• C. Cytoplasm
• D. Chloroplast

Hint:

Think of the cytoplasm as the cellular factory.
The cytoplasm manufactures the components and delivers them via vesicles for extracellular assembly.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The cell wall is an extracellular matrix located outside the plasma membrane.
Its synthesis requires the production and export of complex polysaccharides and proteins from the metabolic machinery of the cell.

Step 2: Detailed Explanation:
Most structural components of the cell wall are synthesized within the active cytoplasm.
Non-cellulosic wall components, such as pectins, hemicelluloses, and glycoproteins, are synthesized inside the Golgi apparatus.
These materials are packaged into secretory vesicles and transported to the cell surface, where they are released by exocytosis.
While the cellulose microfibrils are synthesized at the plasma membrane (plasmalemma) by cellulose synthase complexes, the sugar nucleotide substrates (like UDP-glucose) are produced by enzymes in the cytoplasm.
Thus, the cell wall is considered a primary secretory product of the cell's cytoplasm.
The tonoplast is the membrane of the central vacuole and is not involved in cell wall synthesis.
Chloroplasts are energy-converting organelles and do not directly secrete cell wall components.

Step 3: Final Answer:
The macromolecular components of the plant cell wall are synthesized and secreted by the cytoplasm.