NEET BIOLOGY

Detailed explanation-1: -Lignin is the complex phenolic polymer that strengthens the secondary cell wall of xylem cells, such as water-conducting tracheary elements and supportive fibers, and is most evident in woody tissues of trees.

Detailed explanation-2: -The pit membrane, which lies in the center of each pit, allows water to pass between xylem conduits but limits the spread of embolism and vascular pathogens in the xylem.

Detailed explanation-3: -The continuous flow of water in root xylem is due to transpiration pull. The water is lost through the stomata is replaced by xylem vessel . Evaporation of water molecules cells of cells of leaf creates a suction which pulls water from the xylem of roots to leaves.

Detailed explanation-4: -The walls of xylem cells are lignified (strengthened with a substance called lignin ). This allows the xylem to withstand pressure changes as water moves through the plant.