required practical 1 - microscopes

• 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 instead of a lamp in some optical microscopes?

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

  To magnify the specimen
• 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 are the two focusing dials on the 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
• What should you do after placing the slide on the stage?

  Use clips to hold the slide in place
• Which objective lens should you select first for viewing?

  The lowest power objective lens
• Why is it important to 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?

  Look through the eyepiece and adjust
• What is the purpose of the fine focusing dial?

  To bring the cells into clear focus
• 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?

  Forty times
• What should you do after calculating the total magnification?

  Select a higher power objective lens
• What might you see when looking at animal cells under a microscope?

  Nucleus, cytoplasm, and cell membrane
• What can you see in plant cells under a light microscope?

  Cell wall, cytoplasm, and nucleus
• What additional structures might be visible in plant cells?

  Vacuole and chloroplasts
• How do you include a magnification scale in your drawing?

  Measure the diameter of the field of view
• What should you do after measuring the field of view?

  Show this on a drawing using a scale bar
• What should you write on your drawing regarding magnification?

  The magnification used
• What are the differences between optical microscopes?

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

  Coarse adjusts quickly, fine adjusts slowly
• What are the limitations of detail visible under an optical microscope?

  Only limited structures like nucleus and cytoplasm
• What is the process of adjusting the objective lens?

  Position it close to the slide, then focus
• Why is it important to view from the side when adjusting the lens?

  To prevent damaging the slide
• What types of cells can be observed under an optical microscope?

  Animal and plant cells
• Why is including a magnification scale important in drawings?

  It provides context for the size of cells