Microscopes

• What is the main focus of the topic "The world of the microscope"?

  Cell structure and transport
• What are the learning objectives for the topic on microscopy?

  • Development of microscopy techniques over time
  • Differences in magnification and resolution between light and electron microscopes
  • Calculation of magnification, real size, and image size of a specimen
• What is the maximum magnification of the best light microscopes?

  ×2000
• Why are light microscopes still widely used?

  They are relatively cheap and can magnify live specimens
• When were the first light microscopes developed?

  In the mid-17th century
• What is the main advantage of electron microscopes over light microscopes?

  They can magnify objects up to around 2,000,000 times
• What type of images do transmission electron microscopes produce?

  2D images
• What is a key feature of scanning electron microscopes?

  They provide dramatic 3D images
• What are the limitations of electron microscopes?

  They are large, very expensive, and require controlled environments
• How do you calculate the overall magnification of a light microscope?

  • Multiply the magnification of the eyepiece lens by the magnification of the objective lens
  • Example: If eyepiece is ×4 and objective is ×10, then overall magnification is:

  $4 \times 10 =$$\times 40$
• How should you label drawings made using a microscope?

  Indicate the magnification at which you viewed the specimen
• What units are used for measuring distances in microscopy?

  • 1 kilometre (km) = 1000 metres (m)
  • 1 metre (m) = 100 centimetres (cm)
  • 1 centimetre (cm) = 10 millimetres (mm)
  • 1 millimetre (mm) = 1000 micrometres (µm)
  • 1 micrometre (µm) = 1000 nanometres (nm)
• What is the standard form of a nanometre in metres?

  1 × 10⁻⁹ m
• What is the significance of the development of microscopy techniques over time?

  • Enhanced understanding of cell structure
  • Allowed observation of subcellular structures
  • Improved imaging capabilities with advanced technology
• How do the magnification capabilities of light microscopes compare to electron microscopes?

  Light microscopes can magnify up to ×2000, while electron microscopes can magnify up to 2,000,000 times
• If the eyepiece lens of a microscope is ×10 and the objective lens is ×40, what is the overall magnification?

  $10 \times 40 =$$\times 400$
• What is the formula for calculating the size of an object under a microscope?

  • The formula is not provided in the study material, but typically involves:
  • Size of object = Size of image / Magnification