GED Science Practice

What is the primary function of cellulose in plant-cell walls?

1. Forms energy storage

2. Allows for cell movement

3. Reinforces plant-cell walls

4. Regulates osmotic pressure

The correct answer is: Reinforces plant-cell walls

Cellulose primarily functions to reinforce plant-cell walls due to its structural properties. It is a polysaccharide composed of long chains of glucose molecules, which form strong fibers. These fibers provide rigidity and strength to the cell walls, allowing plants to maintain their shape and resist external pressures. This structural role is critical for supporting the overall integrity of plant tissues and aiding in their upright growth. Additionally, cellulose's strength allows plants to withstand various environmental factors, such as wind and gravity. The robust nature of cellulose is vital for maintaining the plant's structure, making it a key component in the composition of cell walls. In contrast, energy storage involves carbohydrates like starch, and cell movement is typically more related to other cellular components, such as the cytoskeleton. The regulation of osmotic pressure is mainly managed by other cellular mechanisms and solutes, rather than the structural role of cellulose.