cell specialisation

• How are sperm cells specialised?

  - have flagellum for movement which contains lots of mitochondria to supply energy to swim

  - acrosome on head of sperm contains digestive enzymes to penetrate ovum coat
• How are nerve cells specialised?

  - long to cover more distance

  - have branched connections at their ends to connect to other nerve cells and form a network around the body
• How are muscle cells specialised?

  Long so they have space to contract and contain lots of mitochondria to generate the energy needed for contraction
• How are root hair cells specialised?

  They have a big surface area for absorbing mineral ions and water from the soil
• How are phloem cells specialised?

  - cells arranged end to end in tubes

  - end walls are semi permeable to allow sugars through but till support the walls
• How are xylem cells specialised?

  They are hollow in the centre and have very few sub-cellular structures so that stuff can flow through them
• What are stem cells?

  unspecialized cells that are able to renew themselves for long periods of time by cell division
• Sperm Cells

  • Long tail and streamlined head: helps it swim to the egg faster
  • Many mitochondria in the cell provide the energy required
  • Digestive enzymes in its acrosome: digest through the egg cell membrane
• Nerve Cells

  Function: transmit electrical signals from one part of the body to another
• Muscle Cells

  Function: to contract quickly
• Muscle Cells

  • Contain special proteins which slide over each other, causing the muscle to contract
  • Long: space to contract
  • Contain many mitochondria: to release energy needed for contraction
• Root Hair Cells

  Function: to absorb water by osmosis and mineral ions by active transport from soil. Found in the tips of roots
• Root Hair Cells

  • Large surface area due to root hairs: more water can move in
  • Large permanent vacuole effects the speed of movement of water from the soil to the cell
  • Mitochondria: provides energy from respiration for the active transport of mineral ions into the root hair cell