Page 22 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six

Biology for Secondary Schools

Part Function

Fine adjustment knob Rises or lowers body tube in order to bring the image
into sharp focus
Arm Supports the body tube, knobs, stage, diaphragm
FOR ONLINE READING ONLY
and mirror. It is one of the parts that is held when
moving the microscope
Ocular tube Allows light to pass straight from the objective lens
to the eyepiece lens
Stage Surface on which the specimen is placed
Stage clip Holds the slide containing the specimen in place
Mirror Reflects and directs light to the specimen under
observation
Condenser Concentrates light onto the specimen that is placed
on the stage
Diaphragm Regulates the amount of light passing from the
mirror to the condenser
Hinge screw Rises and lowers the stage to keep the specimen in
the correct position for observation
Base Provides firm support for the microscope

How to use the light microscope (e) While looking through the
(a) Place the microscope on the eyepiece, use your hand to adjust
laboratory bench or table. Make the mirror so that the light is
sure it is not too close to the edge. directed to the specimen on the
Position the microscope such that stage. Always keep both eyes
the arm faces you and the stage open when looking through the
faces away from you. eyepiece.
(b) Mount the specimen on the (f) Adjust the coarse adjustment knob
microscope slide. Cover it with a to bring the specimen into focus.
coverslip. (g) Adjust the fine adjustment knob
(c) Make sure that the low objective to bring the specimen into a sharp
lens is in line with the eyepiece focus.
lens.
(d) Place the slide with the specimen Total magnification = eyepiece
on the stage. Hold it in place with magnification × objective lens
the stage clip. magnification

16 Student’s Book Form One Student’s Book Form One

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