you have a DNA sequence that codes for a protein and is 90 nucleotides long. A frameshift mutation occurs at the 31st base. How many amino acids will be correct in this protein​

All, some, one or none. 90 bases ÷ 3 bases/codon = 30 coding triplets.

All will be correct. This sequence is an initial noncoding sequence; therefore, no changes will occur in the polypeptide that follows.

None. Without a MET initiator, the sequence, if altered, won't code.

Some or One. Any triplet shift after 85 base will alter the remaining sequence, possibly an insertion or deletion, which will change the reading frame, resulting in a completely different translation from the original. The new sequence could end shorter if a triplet is changed to a terminator or elongate (runs on) if no terminal codon is read.