Lecture Notes: Specialised Cells and Differentiation

Introduction

• Topics Covered: Specialised cells and the process of differentiation.
• Context: Applies to complex organisms like animals and plants.

Specialised Cells

• Definition: Different types of cells in organisms that have specific roles.
• Examples in Animals:
  • Sperm cells
  • Muscle cells
  • Nerve cells
  • Approximately 200 types in humans.
• Examples in Plants:
  • Root hair cells
  • Phloem cells
  • Xylem cells

Case Study: Sperm Cell

• Role: Deliver genetic material to an egg cell for fertilization.
• Adaptations:
  • Nucleus: Contains half the genetic material of a normal cell.
  • Flagellum: Tail for swimming to the egg.
  • Streamlined Shape: Aids in swimming.
  • Mitochondria: Provides energy for movement.
  • Digestive Enzymes: Helps penetrate the egg cell.

General Characteristics of Specialised Cells

• Have specific roles and are adapted with:
  • Unique shape and structure.
  • Specific organelle composition (e.g., mitochondria).
• Examples:
  • Red blood cells vs. nerve cells — different shapes, structures, and organelles due to different roles.

Differentiation

• Definition: Process by which cells become specialised.
• Example: Human Development
  • Begins as a single cell (zygote).
  • Zygote divides by mitosis into multiple identical cells.
  • Through differentiation, cells become specialised (e.g., muscle, skin, nerve, red blood cells).
• Process Involves:
  • Changes in cell shape and structure.
  • Adjustments in the combination of organelles.

Stem Cells

• Definition: Cells that can divide by mitosis and differentiate into various types of specialised cells.
• Note: Topic to be covered more in-depth in another video.

Additional Information

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End of Lecture Notes