Question

Post-transcriptional modification in eukaryotes is referred as
A. Translation
B. Splicing
C. Sequencing
D. Restriction.

Answer 1

Hint: Transcription is the process of formation of messenger RNA from the DNA by the enzyme RNA polymerase is called transcription. And the sequence of nucleotide base pairs on the strand of mRNA is complementary to the template strand of DNA.

Complete answer:
Transcription occurs in both eukaryotes and prokaryotes.
In transcription, there are 3 stages, which include initiation, elongation, and termination.
The start of transcription begins with the promoter, once the RNA polymerase binds to the promoter site.
Before starting of transcription, an unwinding of the DNA molecule occur and one strand of the DNA molecule act as a template strand, and once the polymerase enzyme bind to the promoter site in a certain sequence and the initiation begins
Then the polymerase enzyme starts moving and the complementary nucleotides bases start forming in mRNA, thymine is absent which is replaced by uracil.
Once the elongation is completed the termination also takes place and the messenger RNA forms, but in eukaryotes, some changes occur to mRNA, which is called post-transcriptional changes.
Post-transcriptional changes
The post-transcriptional changes occur to alter the chemical structure of the mRNA, and this processing includes mainly 3 steps.
Adding 5’ cap, and the addition of 3’ polyadenylation tail and one other process is splicing, these all occur to alter the chemical nature of the formed mRNA.
Normally the mRNA after transcription contains both introns and Extron’s, where Extron’s are coding sequences and introns are noncoding sequence, while introns are cut down by splicing and making mRNA more mature.

So the Correct option: B. Splicing.

Note:
In the processing, 7methylguanosine is added to form the 5’ cap, for this phosphate on 5’ end is removed by the enzyme phosphatase, and at the 3’ end phosphate is removed and 250 adenine molecules and form poly(A) adenylated chain, and the introns, which remove noncoding DNA sequence by splicing.