Specialised animal cells

• What is the process called when cells become specialized?

  Differentiation
• What is the job of a sperm cell?

  To join with an ovum (fertilisation)
• Sperm cell adaptations

  . Contain their genetic information in the nucleus (But only half-23)

  
  

  .Have a long tail which allows them to swim to the ovum- they are also streamlined to make this easier.

  
  

  Sperm cells are packed full of mitochondria. These provide energy needed for swimming.

  
  

  . In the acrosome, the sperm cell contains enzymes which allow them to digest their way through the outer layer of the ovum.
• What is the job of a nerve cell?

  To send electrical impulses around the body.
• Nerve cell adaptations 


  The axon carries the electrical impulses from one part of the body to another.

  
  

  Axon covered with myelin- myelin insulates the axon and speeds up the transmission of nerve impulses.

  
  

  Synapses (at the end of the axon)- Synapses are junctions which allow the impulse to pass from one nerve cell to another.

  
  

  Dendrites-increases the surface area so that other nerve cells can connect more easily.
• Muscle cell adaptations


  muscle cells can contract (get shorter)

  Muscle cells contain protein fibres which can change the length (for contraction)

  When a muscle cell contracts, these protein fibres shorten, decreasing the length of the cell.

  . Packed full of mitochondria to provide energy for muscle contraction

  Work together to form muscle tissue
• Sperm cell

  
• Nerve cell

  
• Muscle cell

  
• Ciliates epithelial cells


  . Line the windpipe (trachea)
• Cilia hair-like structure


  The special hairs on cilia- waft mucus containing lots of bacteria out of the lungs and the trachea into the mouth where it can be swallowed and destroyed by stomach acid.
• Egg cell adaptations

  . Egg cells cytoplasm- contains nutrients for the growth of the early embryo.

  . Haploid number nucleus contains genetic material for fertilisation.

  . Cell membrane changes after fertilisation by a single sperm so that no more sperm can enter
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  Egg cell

  
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  Epithelial cell