AP BIOLOGY

Detailed explanation-1: -All tissues in the xylem except the xylem parenchyma are dead. Their cytoplasm is highly reduced and they only perform the function of conduction. The xylem tissues also lack cell organelles. Therefore, they are considered dead.

Detailed explanation-2: -Xylem can be defined as a complex tissue that is composed of four types of cells-tracheids, trachea, xylem fibre and xylem parenchyma. The only living tissue in is xylem parenchyma.

Detailed explanation-3: -Sclerenchyma: Sclerenchyma cells consist of dead cells they are permanent tissues present in plants. They provide hardness and protection for plants.

Detailed explanation-4: -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.