Specialisation in animal cells

• What is the smallest living organism made of?

  Single cells
• What can single-celled organisms do?

  They can carry out all of the functions of life
• What happens to cells as an organism develops?

  Cells differentiate to form different types of specialised cells
• How do animal and plant cells differ in terms of differentiation?

  Most animal cells differentiate early, while many plant cells can differentiate throughout life
• What changes occur in a cell as it differentiates?

  It develops different sub-cellular structures for a specific function
• What are some examples of specialised cells that work individually?

  Egg and sperm cells
• What is the role of nerve cells in an animal's body?

  They carry electrical impulses and provide rapid communication
• What adaptations do nerve cells have for their function?

  They have lots of dendrites, a long axon, and specialized nerve endings
• How long can the axon of a nerve cell in a blue whale be?

  Up to 25 m long
• What is the function of synapses in nerve cells?


  They pass impulses to another cell using special transmitter chemicals
• What do nerve cells contain to provide energy for transmitter chemicals?

  Lots of mitochondria
• What is the primary function of muscle cells?

  They can contract and relax
• What type of muscle cells work together in tissues called muscles?

  Striated (striped) muscle cells
• How do muscles enable vertebrates to move?

  Muscles contract and relax in pairs to move the bones of the skeleton
• What type of muscle cells form part of the digestive system?

  Smooth muscle cells
• What are the three main adaptations of striated muscle cells?

  They contain special proteins, many mitochondria, and can store glycogen
• How do striated muscle cells contract?

  Special proteins slide over each other to make the fibres contract
• What is the role of mitochondria in muscle cells?

  They transfer energy needed for chemical reactions during contraction and relaxation
• What do sperm cells contain from the male parent?

  Genetic information
• What adaptations do sperm cells have for reaching an egg?

  A long tail, a middle section full of mitochondria, and an acrosome
• What is the function of the long tail in sperm cells?

  It helps move the sperm through water or the female reproductive system
• What is the role of mitochondria in sperm cells?

  They transfer energy needed for the tail to work
• What does the acrosome in sperm cells store?

  Digestive enzymes for breaking down the outer layers of the egg
• What does the large nucleus in sperm cells contain?

  Genetic information to be passed on