Assertion :The stiffness and rigidity of wood is due to the presence of cellulose, hemicelluloses and lignin. Reason: The degree of stiffness depends upon the amount of cellulose in the cell wall.
Assertion :The stiffness and rigidity of wood is due to the presence of cellulose, hemicelluloses and lignin. Reason: The degree of stiffness depends upon the amount of cellulose in the cell wall.
The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibres that are strong in tension and embedded in a matrix of lignin that resists compression. The cell wall is arranged into layers of cellulose microfibers embedded in a matrix of pectin and hemicellulose, and completely coats the outside of the plant plasma membrane. It gives the stiffness and rigidity of wood. Wood has a secondary cell wall, which is a thicker additional layer of cellulose which increases wall rigidity.
So the correct answer is option A.
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibres that are strong in tension and embedded in a matrix of lignin that resists compression. The cell wall is arranged into layers of cellulose microfibers embedded in a matrix of pectin and hemicellulose, and completely coats the outside of the plant plasma membrane. It gives the stiffness and rigidity of wood. Wood has a secondary cell wall, which is a thicker additional layer of cellulose which increases wall rigidity.
So the correct answer is option A.
