TRANSLATION and REGULATION Questions and Answers pdf :-
1. Which binding is inhibited by pactamycin?
A. Aminoacyl-tRNA to the A-site of 30S subunit
B. Initiator-tRNA to 30S/40S initiation complexes
C. Peptidyl t-RNA to the 50S subunit
D. Formation of peptide bond in P site
2. Which of the following act as the blueprint or template for the process of protein synthesis that takes place on ribosomes?
3. Negative regulation of protein synthesis is accomplished by
A. allosteric inhibition
B. the binding of RNA polymerase to the promoter
C. the binding of a repressor to the DNA
D. the binding of a repressor to the RNA polymerase
4. Site in the ribosome from which the tRNA donates amino acids to the growing polypeptide chain is
A. P site
B. O site
C. T site
D. A site
5. When was the genetic code completed?
6. Which stop codon has been found to encode selenocysteine?
7. Which of the following is a nontranslated sequence located between the transcription and the translation start site?
A. Ending frame
B. Leader sequence
C. Trailer sequence
D. Reading frame
8. Which phage always carries a small piece of E.coli genome?
9. The final step of gene expression is protein synthesis, which is also known as
D. none of these
10. What is the maximum number of different amino acids in a polypeptide chain coded by the synthetic polyribonucleotides (UCAG)5?
11. What is the direct cause of cell death by diphtheria toxin?
A. Formation of an ion channel in the cell membrane
B. Inactivation of a translational elongation factor
C. Induction of apoptosis
D. None of the above
12. The development of global regulatory systems in prokaryotes
A. determines the exact location of the cell on the globe
B. aids in DNA replication
C. determines the exact location of the replication site
D. regulates many genes under varying environmental conditions
13. The interaction between the mRNA and tRNA determined the position of amino acid in a polypeptide sequence. This is called the
B. Wobble hypothesis
D. adaptor hypothesis
14. What are the Svedberg values for the subunits of the 70S ribosomes of E. colli?
A. 40S and 30S
B. 50S and 20S
C. 50S and 30S
D. 40S and 20S
15. Which of the following three codons translate as serine (Ser)?
TRANSLATION and REGULATION Questions and Answers ::
16. The role of molecular chaperones is to
A. facilitate binding of ribosomes to mRNA
B. degrade newly synthesized polypeptides that contain inaccurate sequences
C. facilitate binding of RNA polymerase to DNA
D. aid a newly synthesized polypeptide in folding to its proper shape
17. What is the action of tetracycline in prokaryotes?
A. It blocks translocation reaction on ribosomes
B. It blocks peptidyl transferase reaction on ribosomes
C. It blocks the binding of amino-acyl tRNA to the A site of ribosomes
D. Not known with certainity
19. The Shine-Dalgarno sequence is
A. trailer sequence
B. a stop codon
C. the reading frame of a gene
D. a short sequence that acts as a ribosomal binding site
20. Which of the following statement is correct?
A. The size and sequence of introns can be deduced from the cDNA sequence
B. Restriction endonuclease can cleave ss and dsDNA both
C. Restriction fragment length polymorphism (RFLP) is usually formed in coding sequence of a gene
D. Amino acid sequence of a protein can be deduced from corresponding cDNA nucleotide
21. What was the first bacterial genome to be sequenced and made public?
A. Bacillus subtilis
B. Escherichia coli
C. Haemophilus influenzae
D. No bacterial genome has been sequenced yet
23. During amino acid activation a(n)
A. amino acid is bound to tRNA
B. amino acid is bound to mRNA
C. methyl group is attached to rRNA
D. methyl group is attached to an amino acid
24. The nonsense codon(s) is/are
D. all of these
26. Three stop codons, which aids in termination of translation are also known as
A. pause codons
B. nonsense codons
C. missense codons
D. antisense codons
27. The ribosome binding site
A. forms a stem-loop structure in the RNA
B. is located upstream of the promoter sequence
C. is located immediately upstream of the start codon
D. is more likely to be associated with an operon than with a gene encoding a single protein
28. Which of the following molecule catalyzes the transpeptidation reaction?
A. RNA polymerase
B. Peptidyl transferase
C. DNA ligase
D. DNA polymerase
29. Which of the termination codon is called amber?
A. UAA B. UAG
C. UGA D. AUG