Final answer:
Eukaryotic mRNA undergoes several processing steps after transcription and before translation, which include splicing, editing, and polyadenylation, collectively known as mRNA processing.
Step-by-step explanation:
The third extra step that eukaryotes must take with its end product mRNA after transcription and before translation is mRNA processing. This processing includes several crucial alterations - the most noted ones being splicing, editing, and polyadenylation. These changes are essential for converting the pre-mRNA, which is initially formed during transcription, into a mature mRNA that can be translated into protein.
Unlike prokaryotes that often start the translation of an mRNA molecule while it is still being transcribed, eukaryotic cells must transport their newly synthesized mRNA from the nucleus to the cytoplasm for translation, necessitating these additional processing steps to protect the mRNA and ensure its proper functioning.
RNA splicing occurs, where non-coding introns are removed, and the remaining exons are ligated together. This process creates a mature mRNA that contains only the protein-coding sequences. These modifications collectively form mature mRNA, ready for efficient translation in the cytoplasm, ensuring the accurate expression of genetic information in eukaryotic cells.