microscopes rq practical

• What is the central part of the optical microscope called?

  The stage
• What is the purpose of the stage on an optical microscope?

  It is where we place a microscope slide
• What is used to hold the slide in place on the stage?

  Clips
• How does light pass through the microscope slide?

  Light from the lamp passes up through the microscope slide
• What is the difference between some optical microscopes regarding light source?

  Some have a lamp, while others have a mirror beneath the stage
• What are the lenses above the stage called?

  Objective lenses
• How many objective lenses do most microscopes have?

  Three different objective lenses
• 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 final parts of the microscope mentioned?

  The coarse focusing dial and the fine focusing dial
• What is the first step to use an optical microscope to view a prepared slide?

  Place the slide onto the stage and use the clips to hold it in place
• Which objective lens should be selected first for viewing?

  The lowest power objective lens, usually four times
• How do you position the objective lens when using an optical microscope?

  Turn the coarse focusing dial until it almost touches the microscope slide
• 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?

  Look down through the eyepiece and slowly turn the coarse focusing dial
• What is the purpose of the fine focusing dial?

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

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

  Forty times
• What should you do after achieving focus with the lowest power objective lens?

  Select a higher power objective lens, such as ten times
• What should you do after switching to a higher power objective lens?

  Adjust the fine focusing dial to bring the cells back into focus
• 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, cytoplasm, nucleus, vacuole, and chloroplasts
• How should you label your drawing of cells observed under the microscope?

  Use a pencil to make a clear labeled drawing and include a magnification scale
• How do you create a magnification scale for your drawing?

  Measure the diameter of the field of view in millimeters and show this on the drawing
• What should you write on your drawing besides the scale?

  The magnification, for example, 100 times