Go to Figure 5.26a and, for the top three nucleotides,

Pg.1 Chapter 2 chapter 2  Measurements and Significant figures o A measurement is a quantitative observation o Every measurement has a number and units o A unit is a comparison to an agreed standard  They are not arbitrary  Based on a real object of a fundamental property  The Kg is based on a Pl-Ir alloy stored somewhere in France o In scientific measurement every digit is uncertain except for the last one o The last digit is uncertain, and unless states otherwise, has an uncertainty of plus or minus one o Most measurements have uncertainty  No uncertainty in counting sma