Cell Specialisation & Differentiation

• What is the process by which cells specialise?

  Differentiation
• What do cells gain during differentiation?

  New sub-cellular structures
• What are stem cells capable of?

  Differentiating throughout their life
• In which organisms do most cells only differentiate once?

  Animals
• What is a key feature of sperm cells?

  Streamlined head and long tail
• Why do sperm cells have many mitochondria?

  To supply energy for movement
• What is the function of the acrosome in sperm cells?

  Contains enzymes to break down egg membrane
• What is the primary function of nerve cells?

  Transmit electrical signals quickly
• How does the structure of nerve cells aid their function?

  Long axon enables long-distance impulse transmission
• What role do dendrites play in nerve cells?

  Form connections with other nerve cells
• What do nerve endings contain to support their function?

  Many mitochondria for energy
• What is the primary function of muscle cells?

  Contract quickly to cause movement
• What proteins are involved in muscle contraction?

  Myosin and actin
• How do muscle cells generate energy for contraction?

  Through respiration in mitochondria
• What is the function of root hair cells?

  Take up water and minerals from soil
• Why do root hair cells have a large surface area?

  To increase water absorption
• What role does the large permanent vacuole play in root hair cells?

  Affects speed of water movement
• What is the function of mitochondria in root hair cells?

  Provide energy for active transport
• What is the primary function of xylem cells?

  Transport water and minerals up the plant
• What happens to xylem cells upon formation?

  They die and become hollow tubes
• How does lignin help xylem cells?

  Helps withstand pressure from water movement
• What is the primary function of phloem cells?

  Carry products of photosynthesis to all parts
• What do sieve plates in phloem cells allow?

  Movement of substances from cell to cell
• How do companion cells support phloem cells?

  Supply energy through mitochondria
• What must stem cells undergo to become specialised?

  Differentiation
• What happens to genes during differentiation?

  Some are switched on or off
• What is the result of differentiation in stem cells?

  Formation of specialised cells
• What happens to most animal cells after early differentiation?

  They lose the ability to differentiate
• How do red blood cells differ in their ability to divide?

  They cannot divide and are replaced by stem cells
• What is the primary reason for cell division in mature animals?

  To repair or replace damaged cells
• When do plant cells differentiate?

  When they reach their final position
• Can plant cells re-differentiate after moving positions?

  Yes, they can re-differentiate