Animal cells

• Animal are eukaryote ( their DNA is enclosed in a nucleus)
• Organelle in general animal cells:

  • nucleus
  • Cytoplasm
  • Mitochondria
  • Ribosome
  • Cell membrane
• Most animal cells are specialised
• specialised animal cells have adaptations which help them to carry out their particular function, this is called differentiation
• Adaptations of sperm cells:

  Long tail - swim to the ovum

  Lots of mitochondria- provide energy needed for swimming

  Contain enzymes - allow them to digest their way through the outer layer of the ovum
• Sperm cells only contain half the genetic information of a normal human cell
• Nerve cells job is to send electrical impulses around the body
• The axon in nerve cells carry the electrical impulses from one part of the body to another
• Myelin in nerve cells insulate the axon and speed up the transmission of nerve impulses
• The end of the axon in a nerve cell has synapses.(Junctions which allow the impulses to pass from one nerve cell to another )
• The nerve cell has dendrites , which increase the surface area so that other nerve cells can connect more easily
• • Muscle cells contain protein fibres which can change their length
  • when a muscle cell contracts the protein fibres shorten , decreasing the length of the cell
• Muscle cells are packed full of mitochondria to provide energy for muscle contraction
• Muscle cells work together to form muscle tissue
• Job of a sperm cell is to join with an ovum ( egg cell ) for fertilisation