appliedsci microscopes

• What are the two main types of microscopes?

  Light microscopes and electron microscopes
• How is a specimen prepared for viewing under a light microscope?

  It is placed on a slide with a cover slip
• Why should the specimen be thin when using a light microscope?

  So that light can pass through it
• Where does the light usually come from in a light microscope?

  From below the specimen
• What is the purpose of using a stain on a specimen?

  To help see different parts clearly
• What is the eyepiece of a microscope used for?

  To look into the microscope
• What does the objective lens do in a microscope?

  It changes the magnification level
• How do you focus a specimen in a microscope?

  By using the focusing knob
• What is the function of the stage in a microscope?

  To hold the slide with the specimen
• What is the light source in a light microscope?

  A light bulb underneath the specimen
• How does an electron microscope work?

  A beam of electrons is fired at the specimen
• What does a computer do in an electron microscope?

  It produces an image from scattered electrons
• What is a key difference between light and electron microscopes?

  Electron microscopes have much higher magnification
• What is the formula for magnification?

  Magnification = size of image / actual size
• If the actual size is $0.1 \text{ mm}$ and the image size is $20 \text{ mm}$, what is the magnification?


  200
• What is a graticule in a microscope?

  A scale on the eyepiece for measurement
• How do you find the size of cells if the magnification is 400?

  Divide the image size by 400
• What is the conversion of 1 millimeter in meters?

  0.001 meters
• What is a micrometer in scientific notation?

  1 x 10^-6 meters
• What are the advantages of electron microscopes?

  Much greater magnification and detail
• What are the disadvantages of electron microscopes?

  They are expensive and require training
• Why can electron microscopes only examine dead material?

  Because they use fast-moving electrons
• What are the key components of a light microscope?

  • Eyepiece
  • Objective lenses
  • Stage
  • Focusing knob
  • Light source
• What are the strengths and weaknesses of electron microscopes?

  Strengths:

  • Greater magnification
  • Ability to see organelles

  
  

  Weaknesses:

  • High cost
  • Requires special training
  • Only examines dead material