Question Details

Identify the correct statement.

Options

A

The coding strand in a transcription unit is copied to an mRNA

B

Split gene arrangement is characteristic of prokaryotes

C

In capping, methyl guanosine triphosphate is added to the 3' end of hnRNA

D

RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria

Show Answer

Correct Answer :

Option D

RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria

RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria

Solution :

**Correct statement:**
RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria

**Why this statement is true**

1. In many bacteria, transcription termination occurs by a mechanism called **Rho‑dependent termination**.
2. The Rho protein is an ATP‑dependent helicase that attaches to a C‑rich, G‑poor region of the nascent RNA called the **Rho‑utilization (rut) site**.
3. After binding, Rho moves along the RNA in the 5'→3' direction, using energy from ATP hydrolysis.
4. When Rho catches up with the RNA polymerase that is still transcribing the DNA, it destabilizes the transcription complex, causing the RNA polymerase to dissociate from the DNA and release the newly synthesized RNA.
5. Thus, the interaction of RNA polymerase with Rho factor directly leads to termination of transcription in bacteria.

**Why the other statements are false**

1. **“The coding strand in a transcription unit is copied to an mRNA.”**
– Transcription uses the **template (non‑coding) strand** of DNA as the template. The coding strand has the same sequence as the mRNA (except T→U) and is not copied.

2. **“Split gene arrangement is characteristic of prokaryotes.”**
– Genes that are split into separate exons and introns (requiring splicing) are typical of **eukaryotes**. Most prokaryotic genes are continuous (no introns).

3. **“In capping, methyl guanosine triphosphate is added to the 3' end of hnRNA.”**
– The 5' cap of a nascent pre‑mRNA (hnRNA) is a **7‑methylguanosine** attached to the **5' end** via a 5'‑5' triphosphate bridge. No modification is added to the 3' end during capping.

By comparing each option with established molecular biology principles, we see that only the statement about Rho‑dependent termination correctly describes a bacterial transcription process.

Unlock Our Free Library

Access expert-curated educational resources and study materials—completely free.

Ask AI Tutor
5 left
Q1 View Question & Options
AI Tutor is solving this question...
Reading question context & options...