Final answer:
The cell wall in the Kingdom Plantae is a rigid structure external to the plasma membrane comprised mainly of cellulose, which provides protection, support, and shape to plant cells.
Step-by-step explanation:
The Cell Wall in Plantae, The cell wall is a distinguishing feature of Plantae, evident in diagrams such as Figure 4.8 and similar figures in biology textbooks. In the Kingdom Plantae, the cell wall is present and serves multiple functions: it acts as a rigid covering that protects the cell, provides structural support, and maintains the cell’s shape.
Unlike animal cells that lack a cell wall, plant cells—and other organisms such as fungi and some protists—benefit from the added rigidity and protection it offers. The primary component of the plant cell wall is cellulose, a polysaccharide made of glucose units, which contributes to the crunchiness you experience when biting into raw vegetables like celery.
While prokaryotic cell walls are chiefly composed of peptidoglycan, eukaryotic cells such as those in the Plantae kingdom have walls constructed from a variety of substances including cellulose, hemicellulose, and pectin. In many plant cells, an inner secondary cell wall can develop, which contains both cellulose and lignin—adding to their robustness.