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

• Explore more on living organisms:
  • The four components of the blood
  • The skeletal system
  • Skeletal muscles
  • Biomechanics