Biological Drawings and Microscope Calculations

Examining Protists

Parts of the Microscope

Microscope Calculations1. Total Magnification =

magnification of eyepiece x magnification of objective lens

ocular lens = 10X low power = 4X med power = 10X high power = 100XLow TM =Med TM =High TM =

2. Measuring Field of View on Low Poweruse low powerplace clear plastic ruler with mm

markings on top of the stagefocus your imagecount how many divisions of the ruler

fit across the diameter of the field of view

multiply the number of divisions by 1000 to obtain the field of view in micrometers (µm)

record this in µm (1mm = 1000 µm ).

2 mm x 1000 = 2000 µm 3 mm x 1000 = 3000 µm

3. Measuring FOV on other powersex. if at low power FOV is 2000µm, calculate FOV for: 1. med power40X = __?___100X 2000µm? = (40X x 2000µm)

100X= 800µm

2. high power 40X = __?___400X 2000µm? = (40X x 2000µm)

400X= 200µm

4. Estimating Actual Sizeestimate the length of the amoeba based on

the diameter of the field of viewex FOV = 750 µm

amoeba = 40% FOV diameter = 300µm

5. Magnification of the Drawing how many times the drawing has been magnified Magnification of Drawing = drawn size (µm)

actual size (µm)

=100, 000 µm (100 mm x 1000)

300 µm

= 333.3 X

Making Biological Drawings3_HOW TO MAKE BIOLOGICAL

DRAWINGS.pdf