1.4 Specialisation in animal cells

• What is the main focus of Topic B1.4?

  Specialisation in animal cells
• What happens to cells as an organism develops?

  Cells differentiate to form specialised cells
• Why do specialised cells have unique structures?

  To carry out a particular function
• How does the structure of animal cells relate to their function?

  Structure is adapted for specific functions
• What are the synoptic links mentioned in the material?

  • Organisation of specialised cells in tissues, organs, systems (Topic B1.1 and B1.2)
  • Specialised nerve cells (Chapter B10)
• What questions should you ask when observing specialised cells under a microscope?

  How is this cell different in structure?
• What is the second question to consider when observing specialised cells?

  How does the structure help its function?
• What can single-celled organisms do?

  Carry out all functions of life
• How do complex organisms differ from single-celled organisms?

  They are made up of trillions of cells
• What happens to most types of animal cells during development?

  They differentiate at an early stage
• How do plant cells differ from animal cells in terms of differentiation?

  Many plant cells can differentiate throughout life
• What occurs as a cell differentiates?

  Certain genes are switched on or off
• What is a key function of nerve cells?

  Carry electrical impulses around the body
• What adaptations do nerve cells have?

  An axon and many dendrites
• What is the role of the nerve ending or synapse?

  Pass the impulse to another nerve cell
• Why do nerve endings contain many mitochondria?

  To provide energy for transmitter chemicals
• What do muscle cells work together to form?

  Tissues called muscles
• What is the function of striated muscle cells?

  Contract and relax to move bones
• What do smooth muscle cells do in the digestive system?

  Contract to squeeze food through the gut
• What adaptations do striated muscle cells have?

  Special proteins and many mitochondria
• What is the role of glycogen in muscle cells?

  Transfer energy needed for contraction
• What do sperm cells contain from the male parent?

  Genetic information
• Why do sperm cells need to move through water or the female reproductive system?

  To reach an egg for fertilisation
• What adaptations do sperm cells have to aid movement?

  A long tail and many mitochondria
• What is the function of the acrosome in sperm cells?

  Contains digestive enzymes to break down egg layers
• What does the nucleus of a sperm cell contain?

  Genetic information to be passed on
• What are the key points about cell differentiation and specialisation?

  • Cells differentiate to form different types
  • Acquire different sub-cellular structures
  • Acquire special adaptations for functions
  • Examples: muscle cells, nerve cells
  • Function within tissues, organs, systems, or organisms