Lignin is characterized by which of the following features?

Lignin is a complex organic polymer found in the cell walls of various plants, particularly in the woody parts. It provides structural support and rigidity, contributing to the toughness and durability of mature plants. This characteristic is crucial for allowing plants to grow tall and withstand environmental stresses like wind or drought. The presence of lignin also helps protect the plant from pathogens and herbivores by making cell walls harder to digest.

In contrast, soluble fiber is typically made up of components like pectins and gums, which can dissolve in water, while lignin is insoluble. Lignin does not provide sweetness to plants; that function is usually attributed to sugars and carbohydrates. Additionally, lignin is not classified as a digestive polysaccharide, as polysaccharides typically refer to compounds that can be broken down by digestive enzymes, whereas lignin is resistant to such breakdown and is more commonly classified as a form of insoluble fiber.