The polypeptide chain will be six amino acids long after mutation has occurred on the mRNA strand.
The mRNA sequence to be transcribed into the polypeptide chain
If hydroxylamine were applied to cells and caused mutation changing G to A at position 20. It will lead to a change in the amino acid to be produced and also a change in the expected number of amino acids.
Thus, if we have: 5’AUGACCCAUUGGUCUCGUU<u>G</u>GCUGAAGUCA 3’
A change from G to A will change the triplet codon to UAG which is one of the three stop codons signifying the end of translation, thus there will be six amino acids formed.
If a given moth population is at Hardy-Weinberg Equilibrium, we can conclude that the changes in the allele frequency of the population over time is constant. This means that in the absence of evolutionary influences, allele or genotype frequencies remain constant from one generation to the next or so on.