While mrna strands are being created a sequence is sometimes miscopied. what is the best possible outcome for the cell should this take place?

The best possible outcome for the cell in the event of mis-copied mRNA is for the mis-copied sequence to code for the same amino acid as the correct sequence would have done

Explanation: The process of transcription during which the message in DNA is transcribed as genetic codes into mRNA is sometimes not error proof. Synthesized mRNA is usually transported into the cytoplasm where the codes are translated into protein.

Each genetic code which is usually a sequence of 3 purine/pyrimidine bases codes for an amino acid. However, due to the degenerate nature of the genetic codes, more than one codon can code for the same amino acid. The degenerate nature is caused by the fact that there are 64 possible codons and there are 20 amino acids in nature. For example, UUA, UUU and UUG can be coding for the same amino acid in nature.

Hence, if a mistake occur during transcription, the best possible scenario for the cell is that the mis-copied sequence will end up coding for the same amino acid(s) as the correct correct sequence would.