Plant Cell Types and Structures

Introduction

• Plants are living organisms made up of eukaryotic cells.
• Plant cells have distinct characteristics compared to animal cells:
  • Chloroplasts
  • Central Vacuole
  • Cell Wall

Plant Cell Types

Meristematic Cells

• Function: Growth and development, similar to animal stem cells.
• Characteristics:
  • Undifferentiated cells created through mitosis.
  • Can produce any type of plant cell.
  • Do not deplete, allowing indefinite division and growth.
• Location:
  • Apical (tips of roots and shoots)
  • Lateral (side positions in vascular tissues)
  • Intercalary (branch intersections and leaf attachment points)

Parenchyma Cells

• Function: General use, photosynthesis, storage, and transport.
• Characteristics:
  • Thin walls, no specialized structure, varied shapes.
• Roles:
  • Photosynthesis in mesophyll layers of leaves.
  • Storage of starch, fat, and water in roots and seeds.
  • Form structure of fruits and heal plant wounds.

Collenchyma Cells

• Function: Provide flexible structure and support.
• Characteristics:
  • Long cells with thickened cell walls.
  • Contribute to photosynthesis and nutrient storage.
• Roles:
  • Stiffen plant parts, prevent leaves from tearing, allow flexibility.
  • Adapt to environmental conditions (e.g., wind).
• Note: Temporary; replaced by sclerenchyma in woody plants.

Sclerenchyma Cells

• Function: Provide support and structure, specifically in non-growing parts.
• Characteristics:
  • Thick cell walls, primarily dead cells.
  • Contain cellulose and lignin for durability.
• Types:
  • Fibers: Longitudinal support; used in making ropes and fabrics.
  • Sclereids: Form hard structures like nut shells and seed coatings.

Conclusion

• Summary of Cell Types:
  • Meristematic
  • Parenchyma
  • Collenchyma
  • Sclerenchyma
• Cells form tissues that perform different functions within the plant.

Next Steps

• Investigate how plant cells group into tissues and perform various functions.