1.3

• Eukaryotic cells


  Animal and plant cells are examples. They have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.
• Genetic material in eukaryotic cells

  DNA that forms structures called chromosomes contained within the nucleus
• Eukaryotes


  All animals, plants, fungi, and protista
• Prokaryotes


  Bacteria are single-celled living organisms
• Prokaryotic cells


  • Have cytoplasm and a cell membrane surrounded by a cell wall, but the cell wall does not contain cellulose
  • Genetic material is not enclosed in a nucleus, it is a single DNA loop found free in the cytoplasm
  • May also contain extra small rings of DNA called plasmids
• Bacteria


  • 0.2-2.0μm in length
  • Hundreds of thousands could fit on a full stop
  • Grow into visible colonies on agar plates
• Bacteria


  • Can cause diseases in humans, animals and plants
  • Can decompose and destroy stored food
• Orders of magnitude


  Used to make approximate comparisons between numbers or objects. If one number is about 10 times bigger than another, it is an order of magnitude bigger.
• Calculating orders of magnitude

  1. If the bigger number divided by the smaller number is less than 10, then they are the same order of magnitude

  2. If the bigger number divided by the smaller number is around 10, then it is 10^1 or an order of magnitude bigger

  3. If the bigger number divided by the smaller number is around 100, then it is two orders of magnitude or 10^2 bigger
• Eukaryotic cells have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus
• Prokaryotic cells have cytoplasm and a cell membrane surrounded by a cell wall, but the genetic material is not enclosed in a nucleus
• Bacteria are all prokaryotes