Regulation of Gene Expression & Its Types MCQ - Practice Questions with Answers

• Regulation of gene expression refers to a very broad term that may occur at various levels. 
• Considering that gene expression results in the formation of a polypeptide, it can be regulated at several levels. 
• In eukaryotes, the regulation could be exerted at:
  • transcriptional level (formation of primary transcript),
  • processing level (regulation of splicing),
  • transport of mRNA from nucleus to the cytoplasm,
  • translational level.
• In prokaryotes, control of the rate of transcriptional initiation is the predominant site for control of gene expression.
• In a transcription unit, the activity of RNA polymerase at a given promoter is in turn regulated by interaction with accessory proteins, which affect its ability to recognize start sites.

Types of Gene Regulation:

• Inducible:
  • It is a regulation which is switched on in response to the presence of a substrate.
• Constitutive:
  • A regulation is absent.
  • The genes and their proteins remain operational throughout.
• Repressible:
  • It is a regulation in which the activity of the gene is stopped if the product of its activity is already present. 
• Negative Control:
  • The product of a regulatory gene shuts off the expression of genes under its control.
• Positive Control:
  • The product of the regulatory gene activates the expression of genes under its control.