A Level Biology Practice Exam

Which type of cells provide structure and support in plant stems and leaves?

1. Parenchyma cells

2. Collenchyma cells

3. Sclerenchyma cells

4. Meristematic cells

The correct answer is: Sclerenchyma cells

Sclerenchyma cells provide structure and support in plant stems and leaves due to their thick, lignified cell walls that make them rigid and strong. These cells are typically dead at maturity, allowing them to function primarily in providing mechanical support to the plant. Their composition, which includes cellulose and lignin, ensures that they can withstand various physical stresses and maintain the plant's integrity. Parenchyma cells, while common and important for storage and metabolic functions, do not primarily provide structural support. Collenchyma cells do offer some support, especially in young stems and petioles, but their support is flexible, which contrasts with the rigid support provided by sclerenchyma cells. Meristematic cells are undifferentiated and responsible for plant growth and development rather than structural support.