If a cell mistakenly transcribed and translated a gene's intron, the most likely outcome would be A. Additional amino acids would be inserted into the chain.
Introns are non-coding sequences within a gene that are normally spliced out during RNA processing before translation. If an intron is included in the final mRNA and is then translated, it could lead to the incorporation of a sequence that results in a nonfunctional or dysfunctional protein. This misstep in translation can alter the protein's structure and function, often leading to errors in folding or activity.
The other options do not accurately represent the consequence of such an error:
- B is incorrect because the DNA itself would remain unchanged, but the mRNA produced would include the intron.
- C implies a corrective mechanism that typically does not exist for misfolded proteins resulting from this type of mistake; corrections are not guaranteed and often lead to malfunction.
- D is incorrect because introns do not duplicate themselves; they are simply parts of the DNA that can be transcribed but normally are not expressed in the final protein.