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.  

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.