Cell differentiation

• Cells differentiate to form different types of cells:

  • Most animal cells differentiate at early stage and lose ability
  • Most plant cells retain ability to differentiate throught life
• Specialised cells in animals are:

  • Sperm cells
  • Nerve cells
  • Muscle cells
• Specialised cells in plants are:

  • Root hair cells
  • Xylem cells
  • Phloem cells
• Sperm cells:

  • Specialised for reproduction - to get male DNA to female DNA
  • Long tail and streamlined head to swim to egg
  • Lots of mitochondria to provide energy
  • Enzymes in head to digest through egg cell membrane
• Nerve cells:

  • Specialised for rapid signalling - carry electrical signals from one part of body to another
  • Long cells to cover more distance
  • Branched connections at ends to connect to other nerve cells and form network through body
• Muscle cells:

  • Specialised for rapid contraction
  • Long cells for space to contract
  • Lots of mitochrondia to generate energy for contraction
• Root hair cells:

  • Specialised for absorbing water and minerals
  • Grow long hairs that stick out on soil - gives big surface area for absorption
• Phloem and xylem:

  • Specialised for transporting substances - food and water - around plants
  • Cells joined end to end to form tubes
  • Xylem are hollow and phloem have very few subcellular structures so so substances can flow through