Correct option is C
The correct answer is: 3. C only
Explanation :In eukaryotic cells, the processing of mRNA is crucial before it can be exported from the nucleus to the cytoplasm for translation. The necessary modifications for proper mRNA export include:
Capping: A 5' cap structure is added to the mRNA, which is essential for stability and translation initiation.
Splicing: The removal of introns and joining of exons must occur for the mRNA to be functional and ready for translation.
Polyadenylation: The addition of a poly-A tail at the 3' end protects the mRNA from degradation and aids in its export.
Option C (Polyadenylated, spliced, capped mRNA) is the only species of mRNA that meets all these criteria and can therefore be exported to the cytoplasm.
Information Booster:
1.Only fully processed mRNA (capped, spliced, and polyadenylated) is recognized by the nuclear export machinery for transport to the cytoplasm.
2. mRNA species that lack these modifications (such as those in options A, B, and D) cannot be exported to the cytoplasm.
3. After export, the mature mRNA is ready for translation in the cytoplasm.
Additional Information:
A (Unspliced and polyadenylated mRNA): Lacks splicing, making it unsuitable for export to the cytoplasm.
B (Polyadenylated and capped, unspliced mRNA): This species lacks splicing and cannot be exported.
D (Spliced, uncapped, polyadenylated mRNA): This species lacks a 5' cap and cannot be exported.
