AP BIOLOGY

Detailed explanation-1: -Plant Physiology and Development The xylem is composed of dead cells with thick, lignified secondary cell walls. These form a low-resistance pathway for the movement of solution. It comprises both narrow tracheids and vessel elements.

Detailed explanation-2: -Xylem consists of tracheids, vessels, parenchyma, and fibers. Vessels consist of vessel elements joined together in files by large perforation plates, large gaps in the end walls between successive vessel elements, while tracheids have tapering ends that overlap with adjacent cells, and lack perforation plates.

Detailed explanation-3: -Xylem is one of the conductive tissues found in vascular plants and is essential for transporting water and nutrients from roots to shoots. The water-conducting activity of the xylem relies on pipe-like structures consisting of cells called vessel elements.

Detailed explanation-4: -A tracheid is a long and tapered lignified cell in the xylem of vascular plants. It is a type of conductive cell called a tracheary element. Angiosperms use another type of tracheary element, called vessel elements, to transport water through the xylem.