Reasons for the rigidity of the cell wall:

Pectin:
- Pectin is a complex polysaccharide found in the cell walls of plants.
- It helps in holding the plant cells together and provides some degree of rigidity to the cell wall.
- However, pectin alone is not responsible for the overall rigidity of the cell wall.

Lignin:
- Lignin is a complex polymer that provides structural support to the cell walls of plants.
- It is a key component of secondary cell walls in plants, especially in woody plants.
- Lignin contributes to the rigidity and strength of the cell wall, but it is not the main reason for its rigidity.

Hemicellulose:
- Hemicellulose is a group of polysaccharides that are present in the cell walls of plants.
- It plays a crucial role in cross-linking cellulose fibers, providing structural support, and contributing to the rigidity of the cell wall.
- Hemicellulose interacts with cellulose and other components of the cell wall to form a strong and rigid structure.

Cellulose:
- Cellulose is the most abundant organic compound on Earth and is a major component of the plant cell wall.
- It is a linear polymer of glucose molecules that form microfibrils, which are arranged in a crisscross pattern to provide strength and rigidity to the cell wall.
- Cellulose is the primary reason for the rigidity of the cell wall due to its strong and organized structure.
Therefore, hemicellulose, along with cellulose, plays a crucial role in making the cell wall rigid. While pectin and lignin contribute to the overall structure and support of the cell wall, they are not the main reasons for its rigidity.

Lignin