Question

In angular collenchyma, thickenings are present in ______
a. On the tangential walls
b. On the walls bordering intercellular spaces
c. At the corners of the cell
d. Throughout the cell wall

Answer 1

Hint: Collenchyma can serve as storage sites for defensive antibacterial compounds. Collenchyma cells are usually polygonal in shape. There are mainly four types of collenchyma cells: tangential collenchyma cells, annular collenchyma cells, lacunar collenchyma cells, and angular collenchyma cells.

Complete answer:
Cells of collenchyma are elongated with thickened cell walls. It provides structural support for plants. The collenchyma tissues are classified based upon the pattern of wall thickening and cell arrangement, and their location.

The walls of collenchyma will help the plants to shake to mimic the effects of wind. Collenchyma cells help the plant’s organs for elongation and growth of dicotyledonous plants. The collenchyma cells appear as elongated cells having a non-uniform thickened cell wall.

Lignin is usually not present in collenchyma. Thickening materials are deposited only at the corners of the cells. Collenchyma cells are present at the peripheral areas of herbaceous stems, petioles etc. The angular thickenings in collenchymas are rich in cellulose. In a cross-sectional view, the thickenings occur at those places where several cells meet.

Hence, the correct answer is option (C).

Note: Collenchyma is one of the three types of ground tissues present in plants. These cells are absent in monocots, and even in roots of all the plants, though it is present in the dicot leaves above petiole, leaf veins and midrib.