Overview
This lecture explains what specialized cells are, their adaptations, and the process of cell differentiation in animals and plants.
Specialized Cells in Organisms
- Specialized cells perform specific roles within the body of animals and plants.
- Animals have around 200 types of specialized cells, such as sperm, nerve, and muscle cells.
- Plant specialized cells include root hair cells, phloem cells, and xylem cells.
Example: Adaptations of a Sperm Cell
- The nucleus of a sperm cell contains half the genetic material of normal cells to allow fusion with an egg.
- The sperm cell has a tail (flagellum) for swimming to the egg.
- Its streamlined shape aids movement through the uterus.
- Numerous mitochondria provide energy for swimming.
- The front contains digestive enzymes to break into the egg cell.
General Features of Specialized Cells
- Each specialized cell has a unique shape and structure suited to its function.
- The quantity and type of organelles (e.g., mitochondria) differ based on the cell's role.
Differentiation
- Differentiation is the process by which unspecialized cells become specialized.
- Human life begins as a single cell (zygote) that divides into identical cells.
- These cells later differentiate to become specific cell types like muscle, nerve, or blood cells.
- Differentiation involves changes in cell shape, structure, and organelle composition.
Stem Cells
- Stem cells are undifferentiated cells that can divide by mitosis and become specialized.
- Stem cells can develop into various types of specialized cells.
Key Terms & Definitions
- Specialized cell — a cell adapted to perform a particular function.
- Differentiation — the process by which a cell changes to become specialized.
- Zygote — a fertilized egg cell from which new organisms develop.
- Stem cell — a cell capable of dividing and differentiating into different specialized cells.
- Mitochondria — organelles that provide energy for cellular activities.
- Flagellum — tail-like structure enabling cell movement.
Action Items / Next Steps
- Review the lesson linked in the video description.
- Explore the learning platform and complete relevant practice questions.