Quiz on Gene Expression and Transcription

What is the central dogma of gene expression?

• Information flows from DNA to protein to RNA

• Information flows from protein to RNA to DNA

• Information flows from RNA to DNA to protein

• Information flows from DNA to RNA to protein

What is the function of the sigma factor in RNA polymerase?

• Stabilize the mRNA structure

• Remove introns from the mRNA

• Recognize the transcription start site and initiate transcription

• Catalyze the formation of the poly(A) tail

Which enzyme is responsible for adding a 7-methyl guanosine cap at the 5' end of mRNA?

• Guanyltransferase

• Poly(A) polymerase

• Pyrophosphatase

• Endonuclease

What is the role of poly(A) tail at the 3' end of mRNA?

• Promotes mRNA stability and enhances translation

• Cleaves introns from exons

• Initiates transcription

• Adds a 5' cap to the mRNA

Which type of termination mechanism involves the formation of a hairpin structure in the mRNA?

• Splicing termination

• Polyadenylation termination

• Rho-dependent termination

• Rho-independent termination

What is the function of spliceosomes in mRNA processing?

• Catalyze the formation of the 5' cap

• Recognize the promoter region for transcription

• Add a poly(A) tail to the mRNA

• Remove introns and join exons together

Which RNA polymerase is responsible for transcribing mRNAs and some snRNAs in eukaryotes?

• RNA polymerase II

• RNA polymerase I

• RNA polymerase III

• RNA polymerase IV

What is the primary function of RNA polymerase in transcription?

• Synthesize RNA using a DNA template

• Remove introns from the mRNA

• Add a poly(A) tail to the mRNA

• Catalyze the formation of the 5' cap

Which enzyme is responsible for the phosphorylation of ribonucleoside triphosphates during RNA synthesis?

• Guanyltransferase

• Phosphorylase

• Pyrophosphatase

• Poly(A) polymerase

What is the purpose of the 5' cap added to mRNA during post-transcriptional modifications?

• Remove introns from exons

• Prevent degradation of mRNA and aid in translation initiation

• Promote mRNA stability

• Stabilize the mRNA structure