Specialised cells

• Red blood cells : Carry oxygen from the lungs to the body cells.

  Adaptations:

  Biconcave disc shaped makes them flexible to move easily through narrow capillaries.

  No nucleus so allows them to pack more haemoglobin.
• Cialiated and goblet cells- work to keep trachea clear of mucus.

  Goblet-produce mucus
• Nerve cells conduct or transmit impulses around the body.

  Dendrons/axons allow nerve impulses to be transmitted from the cns to the rest of teh body.
• Sperm and egg cells - allows fertilisation and sexual reproduction of offspring which produces greater variation
• Root hair cells- absorbs water and mineral ions

  They have extensions which increases surface area for faster absorbtion of water.

  Thinner cell wall: shorter diffusion distance
• Palisade cells- Function to absorb sunlight to produce sugar by photosynthesis.

  Contains lots of chloroplasts to absorb sunlight for photosynthesis

  Tightly arranged in columns to maximise light absorbtion
• Differences between embryonic and adult stem cells:

  • Embryonic are pluripotent while adult are multi potent
  • Embryonic come from a early stage of an embryo and used to make medicine
  • Extracting embryonic can hurt the donor whereas, adult can be obtained without hurting the donor
  • Adult is used to treat diabetes and cancer