Question

Regulation of gene expression in eukaryotes could be exerted at a. Transcriptional level (formation of primary transcript)
b Processing level (regulation of splicing)
c. Transport of mRNA from nucleus to the cytoplasm
d. Translational level

• A. a, b and c
• B.
  a, b, c and d
• C.
  a, c and d
• D.
  b, c and d

Answer 1

The correct option is B

a, b, c and d
Regulation of gene expression in eukaryotes
In eukaryotes the regulation of gene expression is exerted at four levels
1.Formation of primary transcript at transcriptional level. 2.Regulation of splicing in processing level.
3.Regulation of transporting mRNA from nucleus to cytoplasm. 4.Regulation at translational level.

Regulation at transcriptional level
The primary transcript (RNA) formation from DNA, i.e., transcription is the first step of gene expression. This is one of the steps of regulation of gene expression in eukaryotes which is influenced by various activators and repressors taking part in the process.

Regulation at post-transcriptional level
In eukaryotes, the primary transcript so formed contains introns (non-coding regions) which needs to be removed before translation. This process of removal of introns from primary transcript is called splicing. Splicing factors and spliceosomes regulate this process.

Regulation after transcriptionPart
In eukaryotes, transcription occurs in the nucleus while translation occurs in the cytoplasm. For this purpose, mRNA needs to be transported out from the nucleus in the cytoplasm. Transport of mRNA is also one of the steps of regulating gene expression in eukaryotes.

Regulation at translational level
Translation is the process of synthesising proteins from mRNA. Inhibiting translation results in the inhibition of protein synthesis. Protein synthesis is the final step of gene expression which is regulated by various factors taking part in translational machinery.