Question

The sequence of mRNA transcribed from a piece of DNA having sequence ATTGCATCT is
A. TAAATGGCC
B. UAACGUAGA
C. TAACGTAGA
D. AATTGCAGA

Answer 1

Hint: In transcription, the DNA sequence of the gene is “rephrased” in RNA. In eukaryotic cells, the RNA has to go through additional processing stages for becoming an RNA or messenger RNA.

Complete answer: The mRNA is a single-stranded RNA molecule that correlates to the genetic sequence of genes and is translated by a ribosome in the phase of protein biosynthesis. Transcription is when the RNA is produced of DNA. While transcription, RNA polymerase creates a copy of the DNA gene to mRNA as necessary. This mechanism is quite different in prokaryotes and eukaryotes. Uracil is among the four nitrogenous bases in the nucleic acid RNA depicted by letters A, G, C, and U. The remaining are adenine (A), cytosine (C), and guanine (G). In RNA, uracil attaches to adenine by two hydrogen bonds. Uracil methylation generates thymine. Uracil seems to be a normal, naturally found pyrimidine derivative. Since U replaces T in RNA, the above sequence ATTGCATCT, when transcribed from DNA to mRNA, changes to UAACGUAGA.
So, the correct option is (B).
Additional Information:
Codons in the messenger RNA are read during the translation process, starting with the starting codon and progressing until the stop codon is reached. The mRNA codons are interpreted from 5' to 3'and indicate the sequence of the amino acids in a protein from N-terminus to C-terminus. The reading frame influences how the mRNA sequence is classified into codons during the process of translation. The method of transforming codons into amino acid residues entails two other forms of RNA: transfer RNA, which acknowledges the codon and delivers the appropriate amino acid, and ribosomal RNA (rRNA), the major component of the ribosomal protein manufacturing machine.

Note: Transcription is a process of converting DNA to RNA so that later, the RNA is translated into protein in the form of a polypeptide chain. Thus, the formed polypeptide chain folds into secondary, tertiary, or quaternary structures according to the function it does. RNA replaces uracil in the nucleotide instead of thymine. Uracil is being used in the body that helps perform the metabolism of several enzymes required for cell function by binding to ribose and phosphate.