Q.52 Gene expression is controlled at various stages written below.
Arrange these stages in chronological order:
A. Transcription
B. Translation
C. Post-transcription
D. Epigenetic regulation
E. Post-translation
Choose the correct answer from the options given below.
- A, B, C, D, E
- A, C, B, E, D
- B, C, A, D, E
- D, A, C, B, E
Gene expression regulation occurs in a chronological sequence starting from epigenetic modifications before transcription, followed by processing steps. The correct order aligns with molecular biology principles for NEET/GATE preparation.
Correct Answer
D, A, C, B, E.
Stages Explained
-
D. Epigenetic regulation: Occurs first, involving DNA methylation, histone modifications, and chromatin remodeling that determine if a gene is accessible before transcription begins.
-
A. Transcription: DNA is transcribed into pre-mRNA by RNA polymerase in the nucleus.
-
C. Post-transcription: Includes mRNA processing (capping, splicing, polyadenylation) and export to cytoplasm.
-
B. Translation: Mature mRNA is decoded by ribosomes to synthesize polypeptide chains.
-
E. Post-translation: Protein folding, cleavage, phosphorylation, and other modifications for functionality.
Option Evaluation
Option Evaluation A, B, C, D, E Incorrect; places epigenetic regulation (D) after translation, ignoring pre-transcription control . A, C, B, E, D Incorrect; epigenetics (D) can’t follow post-translation events . B, C, A, D, E Incorrect; starts with translation (B) before transcription (A), violating central dogma . D, A, C, B, E Correct. Follows flow: chromatin access → RNA synthesis → RNA processing → protein synthesis → protein maturation . Gene Expression Stages Overview
Gene expression stages chronological order begins with epigenetic regulation enabling access to DNA, followed by transcription, post-transcriptional processing, translation, and post-translational modifications. This sequence is crucial for NEET biology.
Chronological Sequence Breakdown
Epigenetic regulation (D) precedes transcription (A) by altering chromatin structure. Post-transcription (C) matures pre-mRNA, translation (B) builds proteins, and post-translation (E) activates them.
Exam Strategy for Sequence Questions
Options testing central dogma flow often place epigenetic first. D-A-C-B-E reflects real-time molecular events from nucleus to functional protein.
-
