Feature A is the cell wall.
The feature labelled A in the diagram of a plant cell is the cell wall. The cell wall is a rigid outer layer that surrounds the plant cell membrane, providing structural support and protection. Composed primarily of cellulose, hemicellulose, and other polysaccharides, the cell wall gives plant cells their shape and helps withstand internal turgor pressure.
This structure is crucial for maintaining the overall integrity of plant cells and contributes to the overall strength and rigidity of plant tissues. Unlike animal cells, plant cells have a cell wall as an additional layer outside the cell membrane, serving a protective and supportive function in plant biology.