Help with Biology 103 exam

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

Compare and contrast cladistics and phylogeny. what are their advantages and disadvantages? which is the most useful in understanding how an organism developed into its current form? which concept most strongly supports your opinion about the origin of any given organism?

Which kind of mutation has occurred when the codon for an amino acid is changed to a stop codon? a. a silent mutation b. a missense mutation c. a frameshift mutation d. a nonsense mutation