Question

Cell wall is made up of: ____.

• A. Protein
• B. Lipid
• C. Cellulose
• D. DNA

Hint:

Different kingdoms have different cell wall building blocks! - Plants use Cellulose. - Fungi use Chitin. - Bacteria use Peptidoglycan.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The cell wall is a rigid, non-living outer layer that provides structural support, shape, and protection to plant cells, fungi, and some prokaryotes.

Step 2: Detailed Explanation:
In plants, the primary cell wall is predominantly composed of cellulose, a complex structural polysaccharide made up of linear chains of glucose units. Along with cellulose, the plant cell wall also contains matrix materials like hemicellulose, pectins, and structural proteins.
• Lipids and Proteins are the primary components of the flexible cell membrane (lipid bilayer), not the rigid cell wall.
• DNA is genetic material located inside the nucleus.

Step 3: Final Answer:
The plant cell wall is made up of cellulose.

Answer 2

The question asks for the main structural material of the plant cell wall. Each option is a major class of biomolecule, so we can work through what each one is actually used for in a cell to see which one fits a rigid, protective outer layer.

1. Protein: Proteins are found scattered through the plasma membrane and dissolved throughout the cytoplasm carrying out enzymatic and structural roles, but they are not the bulk material that gives the cell wall its rigidity.
2. Lipid: Lipids form the bilayer of the flexible plasma membrane that lies just inside the cell wall; being fluid and non-rigid, lipids cannot provide the mechanical strength a cell wall needs.
3. Cellulose: Cellulose is a polysaccharide made of long, unbranched chains of glucose units linked together, which bundle into strong microfibrils. These microfibrils give the plant cell wall its rigidity and tensile strength, making cellulose the defining structural material of the wall.
4. DNA: DNA is the hereditary material housed inside the nucleus (and organelles like mitochondria/chloroplasts); it carries genetic information and plays no structural role outside the cell.

Of the four biomolecules listed, only cellulose has the fibrous, load-bearing structure required to build a rigid cell wall.

Therefore, the correct answer is Cellulose.