What are mutations and why do some mutations affect organisms more than others

Did you know that a blue wales tongue weighs more than an elephant?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population. b) the separated population is small, and genetic drift occurs. c) the isolated population is exposed to different selection pressures than the ancestral population. d) different mutations begin to distinguish the gene pools of the separated populations. e) gene flow between the two populations is extensive.

Mrna: gcuaauguc what amino acids does the mrna above code for? what type of amino acids or function are uag, uga, and uaa coding for? which codon (3 letters) signals translation to start and also codes for the amino acid methionine (met)?