Cell Differentiation and Specialisation

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

  Differentiation
• What happens to cells as they differentiate?

  They develop different subcellular structures
• When does most differentiation occur in an organism?

  As the organism develops
• What happens to the ability to differentiate in most animal cells?

  It is lost at an early stage
• What type of cells in mature animals mainly differentiate for repair?

  Skin and blood cells
• What are undifferentiated cells called?

  Stem cells
• What are the characteristics of sperm cells that make them specialised for reproduction?

  • Long tail for swimming
  • Streamlined head
  • Many mitochondria for energy
  • Enzymes in head to digest egg membrane
• How are nerve cells specialised for rapid signalling?

  • Long structure to cover distance
  • Branched connections to form networks
• What features make muscle cells specialised for contraction?

  • Long shape for contraction space
  • High number of mitochondria for energy
• How are root hair cells specialised for absorbing water and minerals?

  • Long "hairs" increase surface area
  • Located on plant root surfaces
• What are the specialisations of phloem and xylem cells for transporting substances?

  • Long and joined end to end
  • Xylem cells are hollow
  • Phloem cells have few subcellular structures
• What is the first stage of human embryonic development?

  Zygote (fertilised egg cell)
• What is the first step in cell division?

  Duplicate the DNA
• Where are chromosomes located in a cell?

  In the nucleus
• What is the process called when the nucleus divides to make identical copies?

  Mitosis
• What happens during cytokinesis?

  The cytoplasm and cell membranes divide
• What is the term for the lifetime process of cells replicating?

  Cell cycle
• What occurs during interphase in cell growth?

  Cells grow and increase organelle numbers
• How are chromosomes pulled during cell division?

  One set is pulled to each end of the dividing cell
• What is the genetic composition of a sperm cell?

  XY chromosomes
• What is the genetic composition of an egg cell?

  XX chromosomes
• What is the role of ribosomes during interphase?

  Increase in number for protein synthesis
• What is the significance of the cell cycle in growth?

  It allows for cell replication and growth
• How does the process of mitosis contribute to genetic continuity?

  It produces identical daughter cells