Q. 50 Which one of the following combinations of polysaccharides is present in plant cell wall?
(A) Only cellulose, hemicellulose and fibroin
(B) Only cellulose, hemicellulose and lignin
(C) Only cellulose, hemicellulose and pectin
(D) Only cellulose, pectin and lignin
The primary polysaccharides in the plant cell wall are cellulose, hemicellulose, and pectin, making option (C) the correct choice for this biology MCQ. This combination provides structural support, flexibility, and adhesion in primary cell walls.
Correct Answer
Option (C): Only cellulose, hemicellulose, and pectin
These three polysaccharides form the core matrix of the primary plant cell wall, with cellulose offering rigidity, hemicellulose cross-linking fibers, and pectin acting as a cementing agent.
Option Analysis
-
(A) Cellulose, hemicellulose, and fibroin: Incorrect, as fibroin is a protein found in insect silk, not a plant polysaccharide.
-
(B) Cellulose, hemicellulose, and lignin: Incorrect, since lignin is a non-polysaccharide polyphenol that lignifies secondary walls, not a primary polysaccharide component.
-
(C) Cellulose, hemicellulose, and pectin: Correct for primary cell walls, where pectin regulates porosity and cell expansion alongside the cellulose-hemicellulose network.
-
(D) Cellulose, pectin, and lignin: Incorrect, as it omits hemicellulose, a key polysaccharide that binds cellulose microfibrils.
