sizes of cells

• Meter


  The base unit of measurement in science
• Sizes in biology

  • Often much smaller than a meter
• Centi

  One hundredth
• Centimetre (cm)

  One hundredth of a meter
• Size of objects

  • Width of little finger is around 1 cm
• Milli

  One thousandth
• Millimetre (mm)

  One thousandth of a meter
• Size of objects

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

  One millionth
• Micrometre (μm)

  One millionth of a meter
• Size of objects

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

  One billionth
• Nanometre (nm)

  One billionth of a meter
• Size of objects

  • Hemoglobin molecule is around 5 nm in diameter
• Prefixes like centi, milli, micro, and nano are used to describe very small sizes in biology
• Cells and their internal structures are often measured in micrometres and manometers