Question

The process of transcription in prokaryotes and eukaryotes differ by. Select the correct option(s):
A. In eukaryotes, there are at least three R Polymerase
B. In eukaryotes, the primary transcripts contain exon and intron
C. In prokaryotes, a single D dependent D polymer is involved
D. In prokaryotes, mR does not require processing to become active

• A. A and D Only
• B. B, C and D Only
• C. A, B and D Only
• D. B and C Only

Hint:

Transcription Comparisons:
Eukaryotes: 3 R Polymerases, Introns present (splicing needed), Post-transcriptiol modifications ($5'$ cap, Poly-A tail).
Prokaryotes: 1 R Polymerase, No Introns, No processing needed (Coupled transcription-translation).

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question tests knowledge of key mechanistic differences in transcription and transcript processing between prokaryotic and eukaryotic organisms.

Step 2: Key Formula or Approach:
Compare prokaryotic and eukaryotic transcription:
• Prokaryotes: Single R polymerase synthesizes all R types; polycistronic mR requires no post-transcriptiol processing; coupled transcription-translation.

• Eukaryotes: Three distinct nuclear R polymerases (Pol I, II, III); monocistronic pre-mR contains exons and introns requiring $5'$-capping, splicing, and $3'$-polyadenylation.

Step 3: Detailed Explation:

• Statement A (True): Eukaryotes express three distinct nuclear R polymerases: R Pol I (rR), R Pol II (mR/snR), and R Pol III (tR/5S rR).

• Statement B (True): Eukaryotic primary transcripts (pre-mR) are interrupted, containing coding sequences (exons) interspersed with non-coding sequences (introns) that must be spliced out.

• Statement C (False): In prokaryotes, transcription is mediated by a single D-dependent R polymerase, not a "D-dependent D polymer(ase)". Thus, C is factually incorrect/a distractor.

• Statement D (True): Prokaryotic mR lacks introns and is translated directly as it is being synthesized (coupled transcription-translation) without post-transcriptiol processing.

Step 4: Fil Answer:
Statements A, B, and D correctly state differences between prokaryotic and eukaryotic transcription.