What peptide would you expect to result from a 21-nucleotide-long dna sequence that contains only the base adenine?

Peptide which you expect to result from a 21-nucleotide-long DNA sequence that contains only the base adenine is definitely a peptide composed of 7 phe.
According to the fact that mino acids code based off then mRNA codons we can see that : . And that's it.

Both prokaryotic and eukaryotic cells have ribosomes and cell membranes