cell specialisation and differentiation

• cell differentiation

  the process of a cell becoming specialised
• function of sperm cell

  To transport the male's DNA to the female's egg
• Adaptations of sperm cell

  streamlined and have a tail to swim to egg

  head contains digestive enzymes to break down egg

  lots of mitochondria for energy
• Function of nerve cells

  To carry electrical signals from one part of the body to another
• Adaptations of Nerve Cells

  long to carry signals long distances

  branched connections to connect to nerves all around the body
• function of muscle cells

  contract for movement
• Adaptations of muscle cells

  lots of mitochondria for energy

  long for lots of space to contract
• Function of root hair cell

  To absorb water and mineral ions for the plant (via osmosis and active transport)
• Adaptations of root hair cells

  large surface area for maximum absorption

  no chloroplasts as there's no light outside
• function of xylem

  transports water and minerals
• adaptations of xylem

  Dead, hollow cells; cell wall contains lignin; contain pits
• function of phloem

  transport food
• adaptations of phloem

  -cell wall with many plasmodesmata.

  -few organelles but no nucleus

  -perforated end walls = sieve plates

  -companion cell with nucleus and many mitochondria for actively loading sucrose etc.