Microscopy

• What should you be able to do by the end of the video?

  Describe how to use an optical microscope
• Why is it important to learn the details of using an optical microscope?

  It could come up in a six mark essay
• What is the main part of the optical microscope where the slide is placed?

  The stage
• What is the function of the lamp in an optical microscope?

  To illuminate the microscope slide
• What do some optical microscopes use instead of a lamp?

  A mirror
• What are the objective lenses used for in an optical microscope?

  To magnify the specimen being viewed
• How many objective lenses do most microscopes have?

  Three
• What are the typical magnifications of the objective lenses?

  Four, ten, and forty times
• What is the magnification of the eyepiece lens?

  Ten times
• What is the purpose of the coarse focusing dial?

  To adjust the distance between the lens and slide
• Why should you look at the microscope from the side while adjusting the objective lens?

  To avoid damaging the slide
• What should you do after positioning the objective lens close to the slide?

  Slowly turn the coarse focusing dial
• How do you bring the cells into clear focus after adjusting the coarse focusing dial?

  Use the fine focusing dial
• How do you calculate the total magnification?

  Multiply eyepiece magnification by objective magnification
• What is the total magnification when using a ten times eyepiece and a four times objective lens?

  $40 \text{ times}$
• What should you do after selecting a higher power objective lens?

  Adjust the fine focusing dial again
• What can you see when looking at animal cells under an optical microscope?

  Nucleus, cytoplasm, and cell membrane
• What additional structures might be visible in plant cells under an optical microscope?

  Cell wall, vacuole, and chloroplasts
• How do you include a magnification scale in your drawing?

  Measure the diameter of the field of view
• What should you write on your drawing besides the scale?

  The magnification used
• Where can you find more questions on this required practical?

  In the vision workbook
• How does the use of a mirror differ from a lamp in optical microscopes?

  A mirror reflects light, while a lamp emits light