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प्रश्न
Give an account of post transcriptional modifications of a eukaryotic mRNA.
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उत्तर
The primary transcripts (hn-RNA) contain both the exons and the introns and are non-functional. Hence, it is subjected to a process called splicing where the introns are removed and exons are joined in a defined order. Intron is the portion of gene which is transcribed but not translated. In prokaryotes, hnRNA is absent so splicing in not required. hnRNA undergoes additional processing called as capping and tailing. In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5′-end of hnRNA. In tailing, adenylate residues (200 - 300) are added at 3′-end in a template-independent manner. It is the fully processed hnRNA, now called mRNA, that is transported out of the nucleus for translation.

Process of Transcription in Eukaryotes
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संबंधित प्रश्न
Explain the process of transcription in Eukaryotes.
Answer the following question.
Construct and label a transcription unit from which the RNA segment given below has been transcribed. Write the complete name of the enzyme that transcribed this RNA.

With regard to mature mRNA in eukaryotes.
Regulatory proteins are the accessory proteins that interact with RNA polymerase and affect its role in transcription. Which of the following statements is correct about regulatory protein?
Methyl guanosine triphosphate is added at 5' end of hn-RNA in a process of ______.
The amino acid attaches to the tRNA at its ______.
In transcription in eukaryotes, heterogeneous nuclear RNA (hnRNA) is transcribed by ______.
Which enzymes are responsible for the synthesis of tRNA?
A ribozyme is an:
Refer the given diagram. What does it represent?

Identify the correct statement.
What are the functions of methylated guanasine cap?
- Assertion: Ribosomal RNA is synthesized in the nucleus of the cell.
- Reason: It is translated with the enzyme RNA polymerase III.
Streptokinase produced by bacterium Streptococcus is used for ______.
Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below:
