Small RNAs with internally complementary sequences that form hairpin‐like structures, synthesized as precursor RNAs and cleaved by endonucleases to form short duplexes are called:

• snRNA

• mRNA

• tRNA

• miRNA

What is the minimum number of NTPs required for the formation of one peptide bond during protein synthesis?

• One

• Two

• Four

• Six

The fidelity of replicative base selection can be reduced by a factor of 10² when the repair of DNA synthesis involves

• AP endonuclease

• ABC exinuclease

• DNA photolyase

• TLS DNA polymerase

The Carboxy-Terminal domain (CTD) of RNA polymerase II consists of heptapeptide repeats (YSPTSPS). Other proteins often bind the C-terminal domain of RNA polymerase in order to activate polymerase activity. Which of the following is not a function asociated with CTD of RNA polymerase?

• Promoter recognition

• Promoter clearance

• 5'-capping

• Splicing

Which of the following is reactive center for splicing of exons during processing of mRNA?

• U1 and U5

• Brnach point, U2 and U6

• Branch point, U4 and U6

• U2 and U4

Which of the following is the first step in translational proof reading?

• Aminoacylation of tRNA by amino acyl tRNA synthetase

• Peptide bond formation

• Entry into A site

• Formation of amino acyl-t-RNA, 40 S ribosome and m-RNA ternary complex

Tetracyclines are a group of broad-spectrum antibiotics against bacterial resistance. Tetracycline antibiotics are proteins synthesis inhibitors and exerts its effects by binding to

• 30 S subunit if ribosome

• 50 S subunit of ribosome

• A site of ribosome

• Peptidyl transferase

Ciprofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class. The target of antibiotic ciprofloxacin is

• Replication

• Protein synthesis

• Cell wall synthesis

• Membrane structure

9.

The melting temperature (Tm) is defined as the temperature at which ahlf of the DNA strands are in the double helical state and half are in the random coil states. Tm of DNA does not depends on

• Length of DNA

• % GC content

• Presence of cations

• Presence of anions

Which eukaryotic RNA Polymerase transcribes t-RNA genes?

• RNA Polymerase I  

• RNA Polymerase II   

• RNA Polymerase III     

• DNA Polymerase I