Summary Required practical 1 (GCSE Biology)

Required Practical 1: Microscope (GCSE Biology
Paper 1)

 The center of the microscope has a stage
 This is where we place the microscope slide
 The stage has clips to hold the slide in place
 Below the stage, there is a lamp
 Light from the lamp passes through the microscope slide
 Some optical microscopes are slightly different
 Rather than having a lamp, these microscopes have a mirror
beneath the stage
 The mirror is used to reflect light up through the microscope
slide
 Above the stage we have a set of lenses
 These are called objective lenses
 Most microscopes have three different objective lenses
 These usually have a magnification of 4x, 10x or 40x
 At the top of the microscope, we have the eyepiece
 This is where we look through
 The eyepiece contains the eyepiece lens which has a
magnification of10x
 The final parts of the microscope are the coarse focussing
dial and the fine focussing dial
Using an optical microscope to view a prepared slide:
 First, we place the slide onto the stage

-Use the clips to hold the slide in place

 We then select the lowest power objective lens

-This is usually 4x

 We need to position the objective lens, so it almost touches
the microscope slide

-To do that, we slowly turn the coarse focussing dial