AP BIOLOGY

Detailed explanation-1: -Tracheids are elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts. Tracheids are one of two types of tracheary elements, vessel elements being the other.

Detailed explanation-2: -> Xylem Fibre: Dead cell with lignified walls and a central lumen. Involved in water transportation and providing mechanical support.

Detailed explanation-3: -This contains shorter, xylary fibers as well as xylem vessels, and both cell types have lignified walls.

Detailed explanation-4: -Industrial wood and paper chemists indicate that lignification is greatest in the thin primary wall and middle lamellae between cells (10).

Detailed explanation-5: -Xylem is a tissue system consisting of specialized cells with lignified secondary cell walls responsible for water movement through the plant. What is lignified? Cells with secondary cell wall thickening typically contain lignin. Lignin is a chemical substance that resists breakdown.