Key concepts in biology Study Guide

When studying cells, scientists often need to measure extremely small dimensions, such as the size of organelles or bacteria. Standard units like metres are too large, so specific prefixes are used to denote fractions of a fundamental unit. These prefixes indicate powers of 10, allowing for convenient representation and comparison of very small measurements. Mastery of these units is crucial for accurate scientific communication and understanding the scale of biological structures. For instance, a millimetre (mm) is one thousandth of a metre, a micrometre (µm) is one millionth of a metre, a nanometre (nm) is one billionth of a metre, and a picometre (pm) is one trillionth of a metre. Converting between these units involves multiplying or dividing by powers of 10. For example, to convert micrometres to nanometres, one would multiply by 1000 since 1 µm = 1000 nm.