The effect of base-pair substitution mutations on protein function varies widely from no detectable effect to the complete loss of protein function (null allele). Why do the functional consequences of base-pair substitution vary so widely?

Why would a mutation in a somatic cell of a multicellular organism not necessarily result in a detectable phenotype?

Most mutations are thought to be deleterious. Why, then, is it reasonable to state that mutations are essential to the evolutionary process?

Why is a random mutation more likely to be deleterious than beneficial?

Most mutations in a diploid organism are recessive. Why?

What is the difference between a silent mutation and a neutral mutation?

Describe the purpose of the Ames test. How are his⁻ bacteria used in the Ames test? What mutational event is identified using his⁻ bacteria?