Final answer:
The correct option is 4. The process of mRNA processing in eukaryotes involves the addition of a 5' cap, 3' polyadenylation, and splicing out introns, but not exons. Exons are the coding segments of mRNA and are retained in the mature mRNA molecule. Thus, the correct option indicating what is not associated with mRNA processing is the 'removal of exons.'
Step-by-step explanation:
The question pertains to mRNA processing in eukaryotic cells. During this process, several modifications occur to transform the initial RNA transcript into a mature mRNA molecule that is ready for translation into a protein. The key steps in mRNA processing include the addition of a 5' methyl guanosine cap, 3' polyadenylation, and the removal of introns through splicing. These steps are crucial as they protect the mRNA from degradation and assist in its export from the nucleus to the cytoplasm, where it will be translated.
However, one of the listed options does not occur as part of the mRNA processing: removal of exons. Exons are the regions of the RNA that contain the actual coding sequence for proteins. In contrast to introns, which are non-coding regions that are removed during splicing, exons are retained and spliced together to form the final coding sequence of the mature mRNA. Therefore, option 4, the 'removal of exons,' is not associated with mRNA processing in eukaryotes.
It's also important to note that option 5, 'removal of exons and introns,' suggests the removal of both coding and non-coding regions, which is incorrect since only introns are removed. The correct answer to this question is option 4, as exon removal is not a part of mRNA processing in eukaryotes.