TRANSCRIPTION and REGULATION Multiple Choice Questions :-
1. The complex of RNA polymerase, DNA template and new RNA transcript is called
A. transcription bubble
B. replication bubble
C. a translation bubble
D. none of these
Answer: A
2. RNA polymerase in prokaryotes has a removable
A. alpha subunit
B. beta subunit
C. both (a) and (b)
D. sigma subunit
Answer: D
3. Promoters for tRNAs are located
A. upstream from the start codon
B. downstream from the start codon
C. both (a) and (b)
D. none of these
Answer: B
4. The binding of lac repressor to DNA could be considered to be analogous to
A. competitive inhibition of an enzyme
B. mixed-type inhibition of an enzyme
C. uncompetitive inhibition of an enzyme
D. allosteric effects in enzyme regulation
Answer: A
5. Rho-dependent termination of transcription in E. coli
A. requires ATP
B. requires about 50 nucleotides of uncomplexed mRNA
C. both (a) and (b)
D. removes mRNA and holoenzyme from the DNA
Answer: C
6. Enhancers are regions that
A. bind RNA polymerase
B. are adjacent to the TATA box
C. are CAT box binding proteins
D. modulate transcription
Answer: D
7. Transcription by E. coli polymerase occurs in
A. four phases known as initiation, propagation, elongation and termination
B. three phases known as initiation, elongation and termination
C. two phases known as initiation and termination
D. none of the above
Answer: B
8. Which of the following is necessary for transcription to occur?
A. DNA molecule
B. RNA polymerase
C. DNA polymerase
D. Both DNA & RNA polymerase
Answer: D
9. Multiple copies of 5S genes, located at a chromosomal site distinct from the other rRNA genes
A. are transcribed by rRNA polymerase III and the 5S rRNA
B. are transcribed by rRNA polymerase II
C. are transcribed by rRNA polymerase I and the 5S rRNA
D. are transcribed by DNA polymerase I
Answer: A
10. Each tRNA molecule has a cloverleaf secondary structure consisting of
A. three stem loops
B. two stem loops
C. four stem loops
D. either (a) or (b)
Answer: A
TRANSCRIPTION and REGULATION Objective type Questions with Answers
11. What is a promoter?
A. A specific sequence of DNA to which a catabolic repressor binds
B. A specific sequence of DNA to which RNA polymerase binds
C. A specific DNA sequence to which a restriction endonuclease binds
D. None of the above
Answer: B
12. The function of the sigma factor of RNA polymerase is to
A. assure that transcription begins at the proper point
B. assure that transcription ends at the proper point
C. assure that translation begins at the proper point
D. assure that translation ends at the proper point
Answer: A
13. In both eukaryotes and prokaryotes, a promoter region that is rich in AT bases is called as
A. CATT
B. Shine Dalgarno region
C. TATA box
D. SV40 region
Answer: C
14. The RNA polymerases that transcribe bacterial DNA are
A. multisubunit enzymes
B. only active inside the cell
C. interchangable with DNA polymerases
D. highly glycosylated in their active forms
Answer: A
15. Immediately after transcription
A. a methylated guanine cap is added to the 51 end of the transcript
B. a methylated guanine cap is added to the 31 end of the transcript
C. both (a) and (b)
D. a poly adenylation signal is added
Answer: A