MAGNIFICATIONS & SCALES

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. 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) 0.2mm X 50mm size of object= 0.5mm • 20mm 50 mm 20mm Magnification = image size50mm = 100x actual size 0.5mm OR a) Magnification = image size (scale) 20mm = 100x actual size (scale) 0.2mm b) 0.2mm = actual size (X) 0.2mm X 25mm width of object= 0.25mm 20mm 25 mm 20mm OR b) Magnification = image size 100 = 25mm = 25/100 = 0.25mm 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 = 63mm63000µm = 7875x ~ 8000x actual size 8µm 8µm • 8000 = X__ 8000 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 = 20,000 / 80000 = 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___ = 40,000µm = 40mm • 20µm • Length ~ 20mm 2000 = 20,000µm 20,000/2000 = 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 = 0.33X actual 43mm