Question

Cell wall of fungi is composed of______.

• A. Pectin
• B. Chitin
• C. Mannans
• D. Cellulose

Answer 1

The correct option is B

Chitin

The correct option is B.

Explanations of the correct option:

1. Chitin is a glucose derivative and a long-chain N-acetylglucosamine polymer.
2. This polysaccharide is the main component of cell walls of fungi, arthropod exoskeletons including crustaceans and insects, mollusc radula, cephalopod beaks, and fish and amphibian scales.

Explanations of the incorrect options:

Option A:

1. Pectin is a compact, acidic heteropolysaccharide present in the primary and middle lamellae and cell walls of terrestrial plants.
2. Galacturonic acid, a galactose-derived sugar acid, is its primary ingredient.

Option C:

1. Mannan is any of a number of mannose-based polysaccharides that are mostly found in plant cell walls.
2. The linear mannans are present in wood as a significant structural polysaccharide and as a storage polysaccharide in the endosperm of palms like Phytelephas macrocarpa as well as in the seeds of other plants like coffee beans and ivory nuts.

Option D:

1. Cellulose is a structural component of the major cell wall of green plants, many algae, and oomycetes.
2. Certain bacterial species secrete it to build biofilms.
3. Cellulose is the most common organic substance on Earth.

Final answer: Cell wall of fungi is composed of chitin.