Question

Differentiate between collenchyma and aerenchyma.

Answer 1

Hint: Growth in plants is mostly moderate to specialized regions of active cell division called Meristems. Generally, meristems are present in the tip of the shoots and roots. Meristems ate of three type’s Primary meristems, intercalary meristems, and secondary meristems. After the development of secondary meristems, it gives rise to permanent cells/tissues.

Complete answer:
Collenchyma is a simple living mechanical tissue.
-Collenchyma is obtained from parenchyma by increasing the length of the cells.
- Cells are delicately arranged without any intercellular spaces.
-Cell wall of collenchyma is composed of pectin.
-Cells appear somewhat elongated, polygonal or rectangular
-Collenchyma gives mechanical support to the growing organs in the plants.
Aerenchyma:
-Aerenchyma is a simple living permanent tissue.
-Aerenchyma is a type of parenchyma mainly present in water plants.
-Cells are loosely arranged to form an intercellular space.
-Cell wall is made up of cellulose.
-Cells are oval, spherical in shape
-Air cavity present in Aerenchyma helps in buoyancy.

Note:
Collenchyma is a supportive living tissue. Enlarged cells with irregular cell walls due to thick deposition of pectin in their cell wall so the cell wall is polygonal in cross-section. In the T.S of dicot stem, leaf, the hypodermis is made up of collenchyma and gives mechanical support to plants.
Parenchyma is the functional tissue in plants and animals. Parenchyma has a large air cavity then it is called aerenchyma. Generally, it is present in the plants which grow on water bodies. Due to the presence of a large air chamber it helps in floating.