1. MAGNIFICATIONS & SCALES
SI UNITS:
1 meter (m)= 1m
1 millimeter (mm) = 10-3m
1 micrometer (µm) = 10-6m
1 nanometer (nm) = 10-9m

2. OR OR 1. (a) Determine the magnification of the string of
Thiomargarita cells in Figure 11, if the scale
bar represents 0.2 mm .
(b) Determine the width of the string of cells.
0.2mm = actual size (X) mm X 50mm size of object= 0.5mm
20mm mm mm
Magnification = image size mm = 100x
actual size mm OR
a) Magnification = image size (scale) mm = 100x
actual size (scale) mm
b) mm = actual size (X) mm X 25mm width of object= 0.25mm
20mm mm mm OR
b) Magnification = image size = 25mm = 25/ = mm
actual size X

3. 2. In Figure 12 the actual length of the mitochondrion is 8µm.
(a) Determine the magnification of this electron
micrograph.
  (b) Calculate how long a 5 µm scale bar would be on
this electron micrograph.
  (c) Determine the width of the mitochondrion.
a) Magnification = image size = mm µm = 7875x ~ 8000x
actual size µm µm
8000 = X__ x 5 = 40,000µm = 40mm
5µm
c) Depending on your measurement location the image width is b/w 20mm & 23mm.
We will use 20mm.
magnification (8000) = 20,000 µm = ,000 / = 2.5µm X

4. 3. The magnification of the human cheek cells from a
compound microscope (Figure 13) is 2000X.
  (a) Calculate how long a 20 µm scale bar would
be on the image.
  (b) Determine the average length of the cheek cells
Magnification (2000) = ___X___ = ,000µm = 40mm
20µm
Length ~ 20mm = ,000µm ,000/ = 10µm X

5. 4.(a) Using the width of the hen’s egg as a guide, estimate
the actual length of the ostrich egg (Figure 14).
(b) Estimate the magnification of the image.
Actual hen egg width = 43mm
Image hen egg width = 15mm
Image ostrich egg = 45mm long
a) Ostrich egg length = 43mm x 45mm = 43 x 3 = 129mm
15mm
b) Magnification = image = 15mm = X
actual mm