Supporting Tissues in Plants | Biology for JAMB PDF Download

Introduction

In plants, supporting tissues play a crucial role in providing mechanical support and strength to different plant parts. These tissues include collenchyma, sclerenchyma, xylem fibers, and phloem fibers. Each tissue has unique characteristics and functions that contribute to the overall structural integrity of plants. This note will provide a comprehensive overview of these supporting tissues according to JAMB Biology.

Collenchyma

• Structure: Collenchyma cells are elongated, living cells with thickened primary cell walls.
• Location: Collenchyma cells are found beneath the epidermis, especially in stems, petioles, and young leaves.
• Functions:
  • Provides flexible support to growing parts of the plant.
  • Allows for bending and stretching without damage.
  • Helps in the transportation of water and nutrients between cells.

Sclerenchyma

• Structure: Sclerenchyma cells are dead cells with highly thickened, lignified secondary cell walls.
• Types: There are two types of sclerenchyma cells: sclereids and fibers.
• Location: Sclerenchyma cells are distributed throughout the plant body, mainly in the stem, bark, and seed coats.
• Functions:
  • Provides rigid support and mechanical strength to mature plant parts.
  • Protects delicate inner tissues from external stressors.
  • Facilitates nutrient transportation in certain plant species.

Xylem Fibers

• Structure: Xylem fibers are dead cells with thick secondary cell walls containing lignin.
• Location: Xylem fibers are present in the xylem tissue, forming part of the vascular bundle in stems and roots.
• Functions:
  • Contributes to the structural support and strength of the plant.
  • Assists in water and mineral transport by forming a network of interconnected cells.
  • Provides mechanical support for long-distance water movement.

Phloem Fibers

• Structure: Phloem fibers are elongated, specialized cells with thin primary cell walls.
• Location: Phloem fibers are located in the phloem tissue, alongside sieve tube elements and companion cells.
• Functions:
  • Provides mechanical support to the phloem tissue.
  • Assists in the conduction of organic nutrients, such as sugars and amino acids, throughout the plant.
  • Helps maintain the structural integrity of the phloem under various environmental conditions.

Conclusion

Understanding the different types of supporting tissues in plants is essential for comprehending the structural framework and adaptive mechanisms of plant growth. Collenchyma, sclerenchyma, xylem fibers, and phloem fibers all contribute to the overall strength and support of plants, each serving distinct roles. By studying these tissues, researchers and students can gain insights into plant physiology, growth patterns, and their responses to environmental stimuli.