Nucleus and DNA storage

• Nucleus - in eukaryotes

  • largest organelle
  • double membrane
  • nuclear pores - allows for movement in and out
  • nucleolus - ribosome production
  • chromatin - DNA and proteins
• Nucleolus


  • ribosome production
  • RNA -> rRNA
  • combines with further proteins to make ribosomes
• Chromatin


  • uncondensed DNA in a complex with histones (proteins)
• Chromosomes


  • condensed and coiled DNA
  • only visible when cells are preparing to divide
• DNA - prokaryotes


  • DNA loops
  • no histones
  • plasmids - circles of DNA