Unit Four - Cells - Microscope Flashcards
Base
Supports the Microscope
Stage
Table where the slide is placed
Light Source
Illuminates Specimen for Clear Viewing
Diaphragm (2)
(What it looks like, function)
- Wheel shaped device
- Regulates amount of light passing through the specimen
Revolving Nosepiece (2)
- Revolving section
- Carries the objective lenses
Objective Lenses (2)
- Different Magnification Powers
- To form an enlarged image
Stage Clips
Secure slide on stage
Ocular (2)
- Brings light rays into focus
- Magnifies image formed from Objectives
Coarse Adjustment Knob (2)
- Moves Stage Up and Down
- Large Focusing
Fine Adjustment Knob (2)
- Moves Stage Slightly
- For Precise Focusing
How do you carry the microscope (3)
- Grasp arm and under the base
- Always hold microscope in an upright position so the eyepiece will not fallout
- Place microscope at least 10 cm from the edge and the arm is facing you
Procedure for focusing on low power (6)
- Place slide on top of stage
- Position 4x lense into optical path, click into position
- Use coarse adjustment knob and place it all the way down
- The move the stage all the way up
- Use fine adjustment knob for sharp focus
- Might need to change the diaphragm for control over the brightness
What is the difference between the procedure of low power and high power?
In high power, you NEVER TOUCH THE COARSE ADJUSTMENT KNOB
Procedure for the Wet Mount Slide (7)
- Obtain the specimen
- Place in center of the slide
- Using dropper, place a drop of water on the specimen
- Hold cover slip at a 90 degree angle
- Make sure the bottom edge is in the drop of the water
- Use probe to lower coverslip on the slide
- Use kimwipe to dry excess water
Why is a light microscope also called a compound microscope? (3)
- Light microscope uses a combo of objective lenses
- 3 objective lenses and the ocular
- To achieve magnification
Why should the specimen be centered in FV on low power before high power? (4)
- Low power provides a larger FV
- Minimum adjustments is needed
- High power provides a smaller FV
- Specimen completely disappear from FV
As magnification increases, apparent size of object
Increase
As magnification increases, actual size of object
Remains the Same
As magnification increases, diameter of FV
Decrease
As magnification increases, ability to see details
Increase
As magnification increases, brightness of image
Decrease
As magnification increases, distance between lense and object
Decrease
How do you find out the field diameter of a different view if you already know the diameter of a lower power?
Magnification of LP X Diameter of LP
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Magnification of Alternate View
How do you find out the field WIDTH of a view if you know the field WIDTH of a different view?
LP Mag/HP Mag = HP FW/LP FW
How to determine the size of object when the object(s) occupy the entire diameter
Diameter of FV/ Num. of objects across the diameter
How to determine the size of object when only one object can fit in the Diameter?
Diameter of FV/% of occ. Diameter
Procedure to determine what thread is on top
- Start at Low Power
- Center Slide
- Use coarse and fine adjustment knob
- Switch to a higher power
- Turn fine adjustment knob toward you
- Thread that comes into focus FIRST is on TOP
- Thread that comes into focus LAST is on the BOTTOM
What happens to an object when placed underneath the microscope?
Becomes upside down and backwards
What is the measure of the field diameter for the 40x, 100x and 400x?
4000 micrometers
1600 micrometers
400 micrometers
