B1- differentiation and specialisation

• What is the process by which a cell changes to become specialized for its job?

  Differentiation
• What happens to cells as they differentiate?

  They develop different subcellular structures and become different types of cells.
• When does most differentiation occur in an organism?

  As the organism develops
• What happens to the ability to differentiate in most animal cells after they become specialized?

  It is lost at an early stage.
• Do plant cells lose their ability to differentiate?

  No, many plant cells do not lose this ability.
• What are the cells that differentiate in mature animals mainly used for?

  Repairing and replacing cells
• What are undifferentiated cells called?

  Stem cells
• What are the functions of sperm cells?

  • Specialised for reproduction
  • Deliver male DNA to female DNA
  • Long tail and streamlined head for swimming
  • Contains mitochondria for energy
  • Carries enzymes to digest the egg cell membrane
• What are the functions of nerve cells?

  • Specialised for rapid signalling
  • Carry electrical signals throughout the body
  • Long structure to cover more distance
  • Branched connections to form networks
• What are the functions of muscle cells?

  • Specialised for contraction
  • Long structure to allow space for contraction
  • Contains many mitochondria for energy generation
• What are the functions of root hair cells?

  • Specialised for absorbing water and minerals
  • Grow into long "hairs" for increased surface area
  • Located on the surface of plant roots
• What are the functions of phloem and xylem cells?

  • Specialised for transporting substances
  • Form phloem and xylem tubes
  • Long and joined end to end
  • Xylem cells are hollow; phloem cells have few subcellular structures
• How do root hair cells increase their efficiency in absorbing water and minerals?

  By growing into long "hairs" that increase surface area.
• What is a key feature of phloem cells that makes them specialised for transporting substances?

  They have very few subcellular structures to allow substances to flow through.
• How does the structure of a sperm cell relate to its function?

  Its long tail and streamlined head help it swim to the egg.
• How do the structures of muscle cells and nerve cells differ in relation to their functions?

  Muscle cells are long for contraction, while nerve cells are long for signal transmission.
• What is the main function of xylem cells in plants?

  To transport water and minerals.
• Why do muscle cells contain a lot of mitochondria?

  To generate the energy needed for contraction.
• What is the main role of phloem cells in plants?

  To transport food substances.
• How does the structure of nerve cells facilitate their function?

  Their long shape allows them to cover more distance for signal transmission.