AP BIOLOGY

Detailed explanation-1: -Sclerenchyma tissue, when mature, is composed of dead cells that have heavily thickened walls containing lignin and a high cellulose content (60%–80%), and serves the function of providing structural support in plants. Sclerenchyma cells possess two types of cell walls: primary and secondary walls.

Detailed explanation-2: -Mature sclerenchyma cells are usually dead cells that have heavily thickened secondary walls containing lignin. The cells are rigid and nonstretchable and are usually found in nongrowing regions of plant bodies, such as the bark or mature stems.

Detailed explanation-3: -The sclerenchyma is called the dead tissue because it lack protoplasm and has thick secondary walls which do not elongate during cell growth. Hence, mature cells get destroyed inside the sclerenchyma tissues. Example: coconut, jute etc.

Detailed explanation-4: -In plants, sclerenchyma is defined as permanent tissue. It loses the property of cell division. Sclerenchyma is dead tissue. They give mechanical support to the plants.

Detailed explanation-5: -Thus, the correct answer is ‘Protoxylem.