​RNA polymerase is an enzyme that transcribes DNA sequences into RNA. Which one of the following is NOT a property of RNA polymerase?

​​

Correct option is B

​RNA polymerases lack proofreading endonuclease activity, unlike DNA polymerases. They exhibit relatively low fidelity compared to DNA polymerases. Errors in transcription are less critical because RNA is not inherited and has a shorter lifespan. RNA polymerases initiate RNA synthesis without primers, transcribe specific DNA regions, and, in eukaryotes, RNA polymerase II transcribes genes encoding ribosomal proteins.

Information Booster:

1. RNA polymerases can initiate RNA synthesis without a primer.
2. They transcribe specific genes or defined DNA regions.
3. RNA polymerase II transcribes mRNA, including ribosomal protein-encoding genes.
4. Errors in transcription are less consequential compared to replication errors.
5. RNA polymerases lack proofreading activity, unlike DNA polymerases.

Additional Knowledge:

• Primer Independence (Option a):
  RNA polymerases do not require primers to initiate transcription. They can start de novo synthesis, unlike DNA polymerases, which require a free 3′-OH group provided by a primer.
• Proofreading Activity (Option b):
  RNA polymerases lack 3′ to 5′ exonuclease activity for proofreading. Errors are tolerated because transcription is not heritable, and mRNA is short-lived.
• Transcription by RNA Polymerase II (Option c):
  In eukaryotes, RNA polymerase II transcribes genes that encode ribosomal proteins, as well as mRNA for other proteins. RNA polymerase I transcribes rRNA (excluding 5S rRNA), and RNA polymerase III transcribes tRNA and 5S rRNA.
• Defined Regions of DNA (Option d):
  RNA polymerase initiates transcription at specific promoter regions, ensuring regulated gene expression.