1: microscopes

• 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 is used in some optical microscopes 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 times, ten times, or forty times
• What is the magnification of the eyepiece lens?

  Ten times
• What are the two focusing dials on an optical microscope?

  Coarse and fine focusing dials
• What is the first step to view a prepared slide using an optical microscope?

  Place the slide onto the stage
• Why should you select the lowest power objective lens first?

  To avoid damaging the slide
• How do you position the objective lens when viewing a slide?

  Turn the coarse focusing dial slowly
• What should you do while adjusting the position of the objective lens?

  Look at the microscope from the side
• What should you do after the objective lens is almost touching the slide?

  Look down through the eyepiece
• How do you bring the cells into focus after looking through the eyepiece?

  Turn the coarse focusing dial slowly
• What is the purpose of the fine focusing dial?

  To bring the cells into clear focus
• How do you calculate the total magnification of a microscope?

  Multiply eyepiece magnification by objective magnification
• What is the total magnification if the eyepiece is ten times and the low-power objective is four times?

  $40 \text{ times}$
• 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?

  Cell wall, vacuole, and chloroplasts
• What should you include in your drawing of cells?

  A magnification scale and labels
• How do you create a magnification scale for your drawing?

  Measure the diameter of the field of view
• What should you do with the ruler when measuring the field of view?

  Place it over the stage
• What should you write on your drawing besides the scale?

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

  In the vision workbook
• What is the purpose of the video?

  To teach 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 are the differences between optical microscopes?

  Some have lamps, others have mirrors
• What is the function of the coarse and fine focusing dials?

  To adjust the focus of the microscope
• How do you make a clear labeled drawing of cells?

  Use a pencil to label the structures
• What are the limitations of detail visible under an optical microscope?

  Limited detail, cannot see organelles
• What types of animal cells can be observed under an optical microscope?

  Depends on the type of animal cell on the slide
• What types of plant cells can be observed under an optical microscope?

  Depends on the type of plant cell on the slide
• Why is it significant to include a magnification scale in drawings?

  To provide context for the size of cells
• How do you measure the diameter of the field of view?

  Using a clear plastic ruler over the stage
• Why is it important to write the magnification on the drawing?

  To indicate the level of detail observed
• Where can you find additional resources for practice questions?

  In the vision workbook