Question

What is the main function of the cell wall?
A. To protect and provide support for the cell
B. Builds protein
C. Convert solar energy to chemical energy
D. Takes in carbon dioxide

Answer 1

Hint: A cell wall is a structure that surrounds the cytoplasm of a cell. It is the characteristic feature of plant cells. It separates the inner components of the cell to the outside. It provides rigidity to plants.

Complete answer: The cell wall performs many functions. Some of the major functions of the cell wall are as given below:
a) The cell wall provides a definite shape to the cell. Thus, it provides support to the cell.
b) The cell wall provides protection against the pathogen and other elements that can harm or destroy it.
c) The cell wall helps in the transportation of the materials from one cell to another cell.
d) The cell wall helps in the apoplastic movement of water in plants.
The cell wall is a dead layer. It is exclusively present in the plant cells only. It is the outermost layer of plant cells. The cell wall of plants is made up of cellulose, hemicellulose and pectins.
The cell wall is made up of three types of layers. These are:
i) Middle lamella – It is the outermost layer of the cell wall. The middle lamella is built up of magnesium and calcium pectate. It behaves as a cementing layer between two adjacent cells.
ii) Primary wall – It is present inside the middle lamella. It is made up of cellulose and hemicellulose. It is fully permeable.
iii) Secondary wall – It is present inside the primary wall. It is rigid and multi-layered. It is made up of cellulose, hemicellulose, pectin, lignin, suberin, etc.
Hence, the correct answer is option A.

Note: The cell wall has channels in between them to facilitate the transport of the substances from one cell to another. The primary wall has minute gaps called the plasmodesmata. The gaps present in the secondary wall are known as pits.