biology paper 1 all in one

• Eukaryotic cells


  Cells that contain their genetic material enclosed in a nucleus
• Eukaryotic cells


  • Contain a nucleus
  • Contain a cell membrane
  • Contain cytoplasm
• Prokaryotic cells


  Cells where the genetic material is not enclosed in a nucleus
• Prokaryotic cells


  • Do not have a nucleus
  • Have a cell membrane
  • Have a cell wall
  • Contain cytoplasm
  • May have plasmids
• Prokaryotic cells


  Are much smaller than eukaryotic cells
• Eukaryotic cells include animal and plant cells
• Prokaryotic cells include bacterial cells
• Meter


  The base unit of measurement in science
• Sizes in biology


  • Often much smaller than a meter
• Centi


  One hundredth
• Centimeter (cm)


  One hundredth of a meter
• Size of objects

  • Width of little finger is around 1 cm
• Milli


  One thousandth
• Millimeter (mm)


  One thousandth of a meter
• Size of objects


  • Tip of a ballpoint pen is around 1 mm
• Micro


  One millionth
• Micrometer (μm)


  One millionth of a meter
• Size of objects


  • Typical human cell is around 10-20 μm in size
• Nano


  One billionth
• Nanometer (nm)


  One billionth of a meter
• Size of objects

  • Molecule of hemoglobin is around 5 nm in diameter
• Prefixes centi, milli, micro, and nano are used to describe sizes much smaller than a meter
• Smaller units like micrometers and nanometers are particularly useful when describing the size of cells and their components