How should molecular clocks be used if not all mutations occur at the same rate?

Which of the following descriptions of proteins are true? i. proteins can have different sequences of amino acids. ii. proteins can have different shapes. iii. proteins can have different numbers of amino acids. a. only i and ii are true. b. only ii and iii are true. c. only i and iii are true. d. i and ii and iii are all true. e. none are true statements

Where can dna be found in a prokaryotic cell

20 the compound al(nh3)2 has atoms of nitrogen.