In: Biology
Which of the following statements is/are TRUE? (i.e. select ONLY the answer(s) that is/are TRUE.)
1.RNA polymerase does not require primer to initiate the process of assembly of nucleotide triphosphates. This is in contrast to DNA replication, where primer is required at initiation.
2.The addition of a Poly-A tail on the end of a transcript happens because of the transcription of the Poly-T signal from the corresponding gene.
3.The molecule Poly-A polymerase is responsible for addition of the Poly-A sequence to the end of an mRNA molecule.
4.Post-transcriptional modification of the 3' ends of eukaryotic mRNA occurs prior to splicing and inside the nucleus.
5.Post-transcriptional modification of the 3' ends of eukaryotic mRNA occurs prior to splicing and outside the nucleus.
6.RNA polymerase requires a primer to initiate the assembly of nucleotide triphosphates. This is identical to the requirement for DNA replication.
7.Post-transcriptional modification of the 3' ends of eukaryotic mRNA is known as polyadenylation.
To begin the reaction, the DNA polymerase requires a primer that consists of free 3’-hydroxyl group, which is paired with the template. This enzyme is unable to begin the synthesis from the scratch without the primer. However, on the other side, the RNA polymerase enzyme does not require any primer and can begin the RNA synthesis.
Polyadenylation refers to the addition of the poly A tail to the mRNA (messenger ribonucleic acid). The poly A consists of multiple adenosine monophosphates or adenine bases. In eukaryotes, it is a part of the process, which releases mRNA for the translation process. It occurs at the 3’end and at 5’end cap takes place. It is done by the poly-A polymerase enzyme.
The RNA splicing is the process where the introns are spliced off. The intronic regions are the non-coding regions of the sequence. They do not code for any amino acids and therefore they are removed before the translation process. The splicing takes place after the post-translation modification within the nucleus.
Hence, options (1), (3), (4), and (7) are true.