Molecular Biology: MCQ on RNA Synthesis (Transcription) & Maturation

       Multiple Choice Question on Transcription (RNA synthesis) and RNA processing

1) Identify the correct statement regarding the function of ribonucleic acid (RNA)
a) messenger RNA (mRNA) serves as a template for the synthesis of proteins

b) Transfer RNA (tRNA) serves as the adapter molecule for the addition of amino acids and elongation of the peptide chain

c) ribosomal RNA (rRNA) serves as machinery for protein synthesis

d) All of the above

2) Which of the following RNA serves the regulatory functions including splicing, and gene silencing?
a) messenger RNA (mRNA)

b) Transfer RNA (tRNA)

c) ribosomal RNA (rRNA)

d) Small Nuclear RNA (snRNA)

3) Which of the following statement is NOT true regarding transcription/RNA synthesis in eukaryotes?
a) RNA synthesis occurs in the nucleus
b) Unlike DNA synthesis, the only selective sequence of DNA is transcribed to RNA
c) RNA synthesis requires a short stretch of RNA primers
d) DNA sequences, specific proteins, and small RNAs regulate RNA synthesis.

4) The pentose sugar moieties are the primary structural difference between DNA and RNA. In addition which of the following is primarily associated with RNA molecule?
a) RNA consists of thymine instead of uracil
b) RNA molecules are highly branched structure
c) RNA molecules have higher structural complexities
d) RNA molecules are anti-parallel and double-stranded

5) In prokaryotes, RNA polymerase catalyzes the synthesis of:
a) mRNA
b) rRNA
c) tRNA
d) All of the above

6) RNA polymerase is a multi-subunit enzyme that recognizes a consensus nucleotide sequence (promoter region) upstream of the transcription start site. 

In prokaryotes, the consensus promoter sequence consists of 5-TATAAT-3' also known as............................................
a) Enhancer box
b) Pribnow box
c) Transcription unit
d) None of the above

7) RNA polymerase catalyzes the synthesis of RNA by adding nucleotide monophosphate and release of pyrophosphate for nucleotide triphosphate. RNA polymerase
a) consists of 5'-3' exonuclease activity
b) lacks 3'-5' endonuclease activity
c) is a high fidelity enzyme
d) All of the above

8) In prokaryotes, a holoenzyme RNA polymerase consists of four core subunits namely 2α, 1β, 1β', and a promoter recognizing σ subunit. It may also require a termination factor for termination of the transcription factor. 

Which of the following is a transcription factor?
a) gamma factor
b) delta factor
c) epsilon factor
d) rho factor

9) Fill in the blank. In prokaryotes, TTGACA is an upstream consensus nucleotide sequence that is required for transcription ............................................ step.
a) Initiation
b) Elongation
c) Termination
d) Capping

10) The termination of transcription occurs in both a rho-dependent and rho-independent manner. Which of the following is NOT true regarding the termination of transcription?
a) rho proteins recognize the C-rich region near 3'end of the newly synthesized RNA
b) rho-independent termination occurs when the transcription reaches the palindromic structure leading to the formation of hairpins
c) rho protein competes with RNA polymerase for binding to nucleotides
d) None of the above

11) Rifamycin is an antibiotic used for the treatment of tuberculosis. It binds to ..................... subunit of RNA polymerase and inhibits the initiation of transcription.
a) α,
b) β
c) σ
d) ζ

12) In eukaryotes, the RNA synthesis process is more complex than in prokaryotes. The RNA synthesis process is regulated by chromatin structure, upstream and downstream sequences, binding partners, etc. Which of the following is TRUE regarding the transcription process in eukaryotes?
a) Most actively transcribed genes are found in a loosely relaxed form of chromatin called euchromatin
b) The most inactive segment of DNA is found in compact chromatin structure called heterochromatin
c) Histone modification such as methylation, and acetylation regulate the RNA transcription by modulating chromatin structure
d) All of the above

13) In eukaryotes, three different RNA polymerases are involved in the synthesis of a different class of RNAs namely: rRNA, tRNA, and mRNA.

Fill in the blank. The RNA polymerase that is required for the synthesis of mRNA is?....................................................

a) RNA polymerase I
b) RNA polymerase II
c) RNA polymerase III
d) None of the above

14) In eukaryotes, the consensus promoter sequences (TATA box) that are required for initiation of transcription are generally present
a) 10 nucleotides upstream of transcription start site (TSS)
b) 25 nucleotides upstream of TSS
c) 10 nucleotides downstream of TSS
d) 25 nucleotides downstream of TSS

15) Enhancers are special cis-acting DNA sequences that increase the rate of transcription by RNA polymerase. 

Which of the following is true regarding enhancers?
a) 10 nucleotide upstream elements
b) 25 nucleotide downstream elements
c) present closer or 1000s nucleotide upstream or downstream of TSS
d) All of the above

16) The capping of nucleotide prevents the rapid cleavage of mRNA and is catalyzed by guanylyltransferase. 

Identify the nucleotide cap that is attached at the 5'end of mRNA.
a) 5-methyl guanosine
b) 7- methyl guanosine
c) 5- acetyl guanosine
d) 7- acetyl guanosine

17) Polyadenylation is a post transcription modification that stabilizes the mRNA and prevents cleavage. 

Fill in the blank. The consensus PolyA sequence is? ................................................
a) (AAGAAA)n
b) (AACAAA)n
c) (AATAAA)n
d) (AAUAAA)n

18) In eukaryotes, the primary transcripts are processed to remove intervening sequences resulting in mRNA, and the process is known as splicing. 

The complex of RNA, and nucleoproteins that execute the splicing process is called:
a) Primosome
b) Splicing fork
c) Spliceosome
d) None of the above

19) The role of small nuclear ribonucleoprotein particles (snRNPs) is....................................................
a) to bind intronic sites and exon segments
b) facilitate the looping of the two exons into the correct alignment for splicing
c) All of the above
d) None of the above

20) The auto-antibodies against the small nucleoproteins are present in
a) beta thalassemia
b) systemic lupus erythematosus
c) Phenylketonuria
d) None of the above

21) The antibody binding diversity is a result of a type of splicing that produces mRNA variants and protein variants by processing different segments of exons. 

The process is known as.......................................................
a) Diversity splicing
b) Alternative splicing
c) Conservative splicing
d) None of the above

22) CAAT box is present in many
a) Prokaryotic promoters upstream of TATA box
b) Prokaryotic promoters are downstream of the TATA box
c) Eukaryotic promoters are upstream of the TATA box
d) Eukaryotic promoters are downstream of the TATA box


Multiple Choice Answers:
1-d) All of the above. These are some of the key functions of RNA.RNA plays a crucial role in gene expression, protein synthesis, and various regulatory processes. 

2-d) Small Nuclear RNA (snRNA). snRNAs are involved in RNA splicing, which is the process of removing introns (non-coding regions) and joining together exons (coding regions) in pre-mRNA.

3- c) RNA synthesis requires a short stretch of RNA primers
4- a) RNA consist of thymine instead of uracil
5- d) All of the above
6-b) Pribnow box
7-b) lacks 3'-5' endonuclease activity
8- d) rho factor
9-a) Initiation
10-c) rho protein competes with RNA polymerase for binding to nucleotides
11- b) β
12- d) All of the above
13-b) RNA polymerase II
14-b) 25 nucleotide upstream of TSS
15-c) present closer or 1000s nucleotide upstream or downstream of TSS
16-b) 7- methyl guanosine
17-d) (AAUAAA)n
18-c) Spliceosome
19-c) All of the above
20-b) systemic lupus erythematosus, 21- b) Alternative splicing
22-c) Eukaryotic promoters are upstream of the TATA box