In microbiology, which unit is most appropriate for measuring the size of a typical virus particle?

• A. Meters (m)
• B. Millimeters (mm)
• C. Nanometers (nm)
• D. Micrometers (µm)

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the typical size range of virus particles. Viruses are generally much smaller than bacteria and other microorganisms, often ranging from about 20 to 300 nanometers in diameter.
2. Step 2: Review the units of length commonly used in microbiology: meters (m), millimeters (mm), micrometers (µm), and nanometers (nm). Each unit differs by a factor of 10^3 from the next smaller or larger unit.
3. Step 3: Convert the size of viruses into these units to see which is most practical. For example, 1 nanometer (nm) = 10^-9 meters, 1 micrometer (µm) = 10^-6 meters, and 1 millimeter (mm) = 10^-3 meters.
4. Step 4: Compare the virus size to these units. Since viruses are on the order of tens to hundreds of nanometers, using nanometers (nm) provides a convenient and precise measurement without resorting to decimals or fractions.
5. Step 5: Conclude that nanometers (nm) is the most appropriate unit for measuring virus size because it matches the scale of virus particles and allows for clear and accurate communication of their dimensions.