Specialized Plant Cells

Specialized Plant Cells

• Cell Differentiation: When a cell develops adaptations to perform a specific function, this process is called differentiation.
• Root Hair Cells: These cells are responsible for absorbing water and dissolved minerals from the soil. They are located on the root surface and have adaptations that increase their surface area for absorption.
  • Root hairs: These extensions increase the surface area of the root, allowing for more efficient absorption of water.
  • Lack of chloroplasts: Since root hair cells are underground and don't receive sunlight, they don't need chloroplasts for photosynthesis.
• Xylem Cells: Xylem cells form long tubes that transport water and dissolved minerals from the roots to the leaves. They have strong, rigid walls to provide support for the plant.
  • Thick walls with lignin: Lignin is a chemical that makes the cell walls strong and rigid, providing structural support. The rigid cell walls cause the xylem cells to die.
  • No end walls: The walls between xylem cells break down entirely, forming a continuous tube for easy water transport.
  • No internal structures: Xylem cells lack nuclei, cytoplasm, vacuoles, and chloroplasts, facilitating water and mineral movement.
• Phloem Cells: Phloem cells transport dissolved sugars (produced during photosynthesis) throughout the plant.
  • Phloem vessel cells: These cells lack nuclei and have limited cytoplasm. The end walls have pores called sieve plates that allow dissolved sugars to move through the cell.
  • Phloem companion cells: These cells provide energy for the phloem vessel cells, as they have fewer mitochondria. Companion cells are connected to phloem vessel cells by plasmodesmata.