Lignin is an adaptation in terrestrial plants. Which statement best explains its role?

• A. Provides structural support
• B. Amino acids synthesis
• C. Absorbs light for photosynthesis
• D. Attracts pollinators

Answer: (A)

Lignin strengthens and waterproofs the walls of plant cells, especially in wood. By being deposited in secondary cell walls, it creates a rigid, hydrophobic network around cellulose fibers. This reinforcement gives tissues like stems and trunks the mechanical support to grow tall and stay upright, and it helps xylem vessels resist the negative pressure generated during water transport. In short, lignin’s primary role is to provide structural support for terrestrial plants (with the added benefit of aiding water transport through waterproofing). The other options describe processes or traits not provided by lignin, such as amino acid synthesis, light capture for photosynthesis, or attracting pollinators.