Chapter 22, Problem 1A

Summary Introduction

To write:

The difference between sclerenchyma and collenchyma.

Introduction:

Along with cell wall in plant, cell there are many different cells that have specific function and form tissue. There are three types of cells that form the plant tissues. They function together to provide food production and storage; give flexibility, support, and strength to the plants. Parenchyma is the most flexible and thin cell found in the plants. They are responsible for the structure of plants and have many other function like food storage, gas exchange, photosynthesis, and protection. The next cell is collenchyma; they are cylindrical in shape and give support around the cell. They consist of unevenly thickened cell walls. This cell retain the ability to process cell division ones get matured. The third cell is the sclerenchyma; they are lack of cytoplasm and other living components ones get mature. They have thick and rigid cell wall; they involve in providing support to the cell and also help in transportation of materials within the cell.

Explanation of Solution

Sclerenchyma cells are formed of dead cells while collenchyma cells are made of living cells. Sclerenchyma have thickened wall and it is uniform. The cell wall is made of either cellulose or lignin or both while the cell wall of collenchyma is thick and made of cellulose. The pits of sclerenchyma cells are mostly simple and oblique and branched while the pits of collenchyma cells are simple and straight. The sclerenchyma tissue provides mechanical support to the plants while the collenchyma cells provide mechanical strength as well as elasticity. The sclerenchyma cells are formed in the area that has stopped elongation while the collenchyma cells help the organs of plants to stretch and elongate. The scelerenchyma cells provide hardness while the collenchyma cell is responsible for the soft tissue. The refractive index of sclerenchyma cells is low compared to collenchyma cells.

Conclusion

The sclerenchyma cells are made of dead cell; they provide hardness, and mechanical strength to the plants with low refractive index. Collenchyma cells are made of living cells and provide softness, mechanical strength and elasticity to the plants with high refractive index.