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Understanding Specialised Plant Cells

Apr 26, 2025

Specialised Plant Cells - KS3 Biology

Key Points

  • Cells are the basic unit of all living organisms.
  • Specialised plant cells perform specific functions due to their unique components.
  • Key types of specialised plant cells include:
    • Root hair cells
    • Palisade cells
    • Xylem cells
    • Phloem cells

Overview of Specialised Plant Cells

Basic Plant Cell Structure

  • Plant cells have a nucleus, a cell membrane, and cytoplasm.
  • Unique to plant cells: vacuole, chloroplasts, and a cell wall.

Specialised Cells

  • Root Hair Cells

    • Lack chloroplasts as they are underground and do not require light absorption.
    • Have a large surface area to efficiently absorb water and minerals from the soil.
  • Palisade Cells

    • Located beneath the surface of leaves.
    • High concentration of chloroplasts (about 70%) for maximum sunlight absorption.
    • Vital for photosynthesis, making them green and suitable for sugar production.
  • Xylem Cells

    • Transport water from roots to leaves.
    • Dead cells with disintegrated end walls to form continuous tubes.
    • Thick cell walls provide structural support to the plant.
  • Phloem Cells

    • Transport sugary water from leaves to other parts of the plant.
    • Unlike xylem, phloem cells are alive and located near xylem in stems.
    • Companion cells with numerous mitochondria facilitate energy release from glucose for transportation.

Detailed Functionality

Root Hair Cells

  • Tiny hairs increase surface area for better absorption of water and minerals.

Palisade Cells

  • Positioned at the top of leaves for optimal light capture.
  • Abundant in chloroplasts for photosynthesis.

Xylem Cells

  • Form long tubes for water transportation and plant support.

Phloem Cells

  • Work in conjunction with companion cells to transport nutrients efficiently.

Test Your Knowledge

  • Quiz and Test Questions
    • Describe adaptations of root hair and palisade cells.
    • Describe the purpose and adaptations of xylem and phloem cells.
    • Answers:
      • Root hair cells have tiny hairs to increase surface area for absorption.
      • Palisade cells have many chloroplasts for photosynthesis and are well-placed for light absorption.
      • Xylem cells are tube-like for water transport, with strong walls for support.
      • Phloem cells carry nutrients, are alive, and have energy-supporting companion cells.

Additional Resources