Question

Which of the following defines the chemical nature of thickening?

A. Pectin with cellulose
B. Lignin with cellulose
C. Pectin with suberin
D. Lignin with suberin

Answer 1

Within the plants, simple, permanent tissues are present. Just one type of cell is made up of these tissues that come together to perform a specific function. One such simple permanent tissue, which is composed of living plant cells, is collenchyma.

Complete answer: Collenchyma tissues are primarily located in young stems in the large veins of leaves under the epidermis. The cells are made up of living, elongated cells that run parallel to the length of the organs in which they are located. The cells of collenchyma have dense cellulose cell walls that thicken at the corners. There are absent or very small intercellular air spaces. The cells contain living protoplasm and chloroplasts are also present in them. Collenchyma cells are typically classified into four major groups by botanists: angular (thickened at intercellular contact points), tangential (cells organized in orderly rows and thickened at the tangential face of the cell wall), annular (uniformly thickened cell walls) and lacunar (intercellular space collenchyma). The collision cell wall is not made of cellulose, suberin, or lignin. Pectin with cellulose defines the chemical nature of thickening.

Collenchyma tissues are primarily located in young stems in the large veins of leaves under the epidermis. The cells are made up of living, elongated cells that run parallel to the length of the organs in which they are located. The cells of collenchyma have dense cellulose cell walls that thicken at the corners. There are absent or very small intercellular air spaces. The cells contain living protoplasm and chloroplasts are also present in them. The cells of collenchyma normally live and have only a thick primary cell wall consisting of cellulose and pectin.
Thus, the correct answer is option A.

Note: It should be noted here that the primary function of collenchyma is to provide the plant with mechanical support. Often there is also chloroplast in them, and then these cells can perform photosynthesis as well.