Question

question 3
which one of the following statements about rna processing is false?
a introns are cut out before mrna leaves the nucleus.
b snrnps function in rna splicing.
c rna splicing can be catalyzed by rna polymerase.
d a primary transcript is often much longer than the final rna molecule that leaves the nucleus.

Explanation:

• Option A: Introns are indeed removed (cut out) during RNA processing before mRNA exits the nucleus. This is a normal part of mRNA maturation.
• Option B: Small nuclear ribonucleoproteins (snRNPs) are key components of the spliceosome, which is responsible for RNA splicing.
• Option C: RNA splicing is catalyzed by the spliceosome (a complex of snRNPs and other proteins), not by RNA polymerase. RNA polymerase is mainly involved in transcription (synthesis of RNA from DNA template).
• Option D: The primary transcript (pre - mRNA) contains introns and exons. After splicing (removal of introns), the final mRNA is shorter as introns are cut out.

Answer:

C. RNA splicing can be catalyzed by RNA polymerase.