Question

In plant cell walls, the tensile strength of the walls are provided by,
A. cellulose
B. lignin
C. pectin
D. extension

Answer 1

Hint:- We should think about the plant physiology in which the materials are present in the cell wall are discussed and also it is in the transporting of minerals and water etc discussed. It said which molecule provides stress/force per unit area.

Complete Answer:-Tensile strength measures the force required to pull something such as rope, wire etc. to the point where it breaks. The tensile strength of a material is defined as the net force per unit area before its failure.
Tensile strength is the maximum stress caused by a pulling force so that a material can withstand without failing as the result of the molecules or atoms holding together or being elastic when being pulled apart while the strength of plant fibre is the maximum stress a material can remain unchanged without falling.
Generally, the tensile strength of the plant is provided by permanent tissue I .e.by collenchyma.
It is the Collenchyma tissue, which explains that these cells are generally long, have irregular thick cells, and provide mechanical strength and support to the structure. These thick cell walls are mainly made up of compounds like pectin as well as cellulose. These are densely packed called pectocellulose .
The cellulose molecules provide tensile strength to the primary cell wall of the plant. Each molecule consists of a linear chain of at least 500 glucose residues that are linked to one another by hydrogen bonds to form a ribbon-like structure, which is stabilized by hydrogen bonds within the chain. And it forms a covalently bonded molecule, which is more stable also.
So from above the explanation, we conclude that the cellulose molecule provides tensile strength.

Hence option A is correct.

Note:- As it is a data-based question so we have to remember it, therefore, we answer this type of question .As we know cellulose is made from glucose having hydrogen bonds so we can directly choose it.