Anormal polypeptide includes the following sequence of amino acids(note: each amino acid is named by a three-letter abbreviation.)

iso-leu-pro-val-his-ser-thr-met

after a mutation, the amino acid sequence becomes the following:

iso-leu-pro-val-tyr-arg-iso-gly

which of the following changes to a nitrogenous base in mrna is most likely to have occured?

a. a cytosine(c) was replaced with uracil(u).
b. a uracil(u) was replaced with a thymine(t)
c. an adenine( a) was removed and not replaced
d. the codon acu was removed and not replaced

C

Explanation:

The mutation seen is most likely due to a frameshift mutation. A nucleotide was added or removed without replacement. This shifted the codon reading sequence by one nucleotide. Therefore the codon downstream of the mutation will code for different amino acids.  

not the best question format lol but what i think might as scale color is controlled by a single gene with two alleles, the green allele and the yellow allele. when moths that are homozygous for green scales are mated with moths that are homozygous for yellow scales, 100% of the offspring have green scales.

answer; i believe that the correct answer is(d) nondisjunction during meiosis;