AP BIOLOGY

Detailed explanation-1: -Xylem vessel cells are dead cells as their nucleus degenerates as the cells mature.

Detailed explanation-2: -The xylem contains a variety of elements-tracheids, vessels, xylem fibers, and xylem parenchyma. Xylem vessels always push water upwards and nutrients towards roots. Tracheids are dead tubular cells with tapering ends, vessels with thin elongated structures that have a tubular appearance, and no cytoplasm.

Detailed explanation-3: -Xylem is a plant tissue which is complex and is responsible for water transportation and nutrients to the plants. Xylem vessel cells can be both alive and dead. But according to the researchers and botanists xylem tissue elements are alive except for the parenchyma which is dead. Hence, the xylem is a dead tissue.

Detailed explanation-4: -Final answer: Sclerenchyma tissues have dead cells.

Detailed explanation-5: -Tracheids, vessels and xylem fibres are dead when mature.