Question

The dead cell observed under the microscope is similar to
A. Cork cell
B. Collenchyma
C. Sclerenchyma
D. Both A and C

Answer 1

Hint: Both cork cell and sclerenchyma cells are dead. The deposition was found on the walls of these cells due to which they are impermeable to water and gases. Cork cells are the part of the dermal tissue system and sclerenchyma cells are the part of the ground tissue system.

Complete answer: A mature cork cell is dead (non-living) as they gradually lose their protoplast. There is a deposition of a waxy substance called suberin on their cell wall which is highly impermeable to gases and water. Robert Hooke observed the cork cell under the primitive microscope and it's only the cell wall that is visible because the cell has already dried out. Cork cells are the part of the dermal tissue system and the dermal tissue is responsible for absorption. Sclerenchyma cells are also found in plant tissues. Mature sclerenchymatous cells are dead cells because there is a deposition of lignin on their cell wall due to which these cells become impermeable to water and gases. Also, their cell walls consist of cellulose and hemicellulose. Sclerenchyma cells are part of the ground tissue system. The major function of a sclerenchyma cell is to provide support. Collenchyma cells are living supporting tissue cells with irregular walls. These are living since they have vacuolated protoplasts. Collenchyma cells have thick deposits of cellulose in their cell walls.
Hence, the correct answer is option D.

Note: There are three types of cells found in plant tissues; the parenchyma, the collenchyma and the Sclerenchyma. Out of which, sclerenchyma is dead supporting tissue. Cork cells form the outer layers of both root and woody stem tissue.