Question

Cell wall in higher plants is made up of
A. Cellulose and protein
B. Cellulose and pectin
C. Cellulose and suberin
D. Cellulose and lipid

Answer 1

Hint: Cell wall is the distinct feature of plant cells. It provides rigidity and shape to the cell. It is present in the plant cells, bacteria, algae, fungi, and some archaea. Prokaryotic cell wall differs from that of eukaryotes.

Complete Answer:
Cell wall is a highly complex structure which is located outside the plasma membrane. It is absent in animal cells.

Composition of cell wall: Cell wall is composed of cellulose fibres which are embedded in a water saturated matrix of polysaccharide and structural glycoprotein. The cellulose fibrils provide tensile strength to the plant cell; pectin is an oligosaccharide which plays an important role in cell wall extension and plant growth. In higher plants, the primary cell wall is made up of cellulose, hemicelluloses and pectin. Pectin is also found in middle lamella.

- Suberin: It is present in the cell wall of woody plants.
- Lipids are present in the cell membrane.
- Proteins: Chitin a polymer of protein is present in the cell wall of fungi.

The correct answer is (B). Cell wall is composed of cellulose and pectin.

Note: Pectin acts as a gelling agent which is found only in plants. It also provides strength to the cell wall. The primary role of a cell wall is to provide mechanical strength to the plants and protect the cell from the outside environment.