Cell Specialisation
When cells develop special structures to perform specific functions, they undergo differentiation. Before specialization, these cells are called stem cells. Let's explore some fascinating specialized cells in both animals and plants!
Animal Cell Specializations:
- Sperm cells have a streamlined head with digestive enzymes (acrosome) to penetrate egg cells. Their flagellum allows movement, while abundant mitochondria provide energy for swimming to the egg.
- Muscle cells contain special proteins (myosin and actin) that slide over each other during contraction. Their elongated shape provides space to contract, and numerous mitochondria generate energy for movement.
- Nerve cells have a long axon to carry electrical signals across distances. Their multiple branches (dendrites) connect to other nerve cells, while nerve endings contain mitochondria that power the production of neurotransmitters.
Did you know? Your body contains about 200 different types of specialized cells, each with its own unique structure perfectly designed for its function!
Plant Cell Specializations:
- Xylem cells transport water upward through plants. They develop strong walls with spiraling lignin deposits before dying and forming hollow tubes that carry water from roots to shoots.
- Root hair cells increase surface area to absorb more water and minerals. They contain many mitochondria for active transport and large vacuoles to speed water movement from soil to cell.
- Phloem cells transport food throughout the plant. Their cell walls break down to form sieve plates, while companion cells with numerous mitochondria keep them alive.
