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 Q.1-Which of the followings does NOT need a primer in order to function?

a)  DNA Pol I

b)  DNA Pol II

c)  DNA Pol III

d) RNA polymerase

Q.2-How many hydrogen bonds form between U and A in a Watson-Crick base pair interactions?

a) 0

b) 1

c) 2

d)  3

Q.3-Which of the followings is required for end to end  joining of DNA

a) DNA Pol I

b) DNA ligase

c) DNA Pol III

d) RNA polymerase

Q.4- The only methylated base in mammals is?

a)7-methyl guanine

b) Thymine

c)  Methyl adenine

d) 5-methyl cytosine

Q.5- The only nucleoside with base to sugar C-C linkage is-

a) Thymidine

b) Pseudouridine

c) Cytidine

d) Adenosine

Q.6- Repressor molecules bind to the:

a) Promoter

b)Enhancer

c) Operator

d) Hormone response element

Q.7- Which of the following enzyme(s) can remove or insert supercoil twists into circular DNA?

a) Topoisomerases

b) DNA Pol II

c) Spliceosomes

d) Helicase

Q.8-Nucleosomes

a) Bind to RNA pol II

b) Package prokaryotic DNA

c) Are only present in prokaryotes

d) Are composed on an octamer of histones and ~150 bp of DNA

Q.9- Which of the following m RNA s lack poly A tail?

a) Ferritin

b) Interferon

c) Insulin

d) None of the above.

Q.10-The RNA primer is removed from the Okazaki fragment by:

a) DNA Pol I

b) DNA Pol II

c) DNA Pol III

d) RNA polymerase

Q.11-Histones have an abundance of which of the following amino acids?

a) Lysine and arginine

b) Alanine and glutamine

c) Glycine and Glutamine

d) Arginine and Glutamine          

Q.12-Which of the following is not a cloning vector?

a) Helicase

b) PBR322

c) SV40

d)  E.coli genomic DNA

Q.13-Which of the following is false about the E. coli Lac operon?

a) It is polycistronic

b) It is an example of negative control

c) The presence of lactose acts as an inducer

d) The repressor binds to the promoter

Q.14-The part of the bacterial RNA polymerase responsible for recognizing the promoter is the:

a) Alpha subunit

b) Rho protein

c)DNA Pol III

d) sigma subunit

Q.15- Enhancer regions in eukaryotic DNA are -

a) DNA Pol I binding sites

b) Inhibit the binding of repressor

c) Enhance the frequency of transcription

d) Specific for given set of genes

 Q.16- In contrast to DNA polymerase, RNA polymerase

a) Fills in the gap between Okazaki fragments

b) Works only in 5`to 3` direction

c) Edits as it synthesizes

d) Synthesizes RNA primer to initiate DNA synthesis.     

Q.17- DNA is replicated:

a) Conservatively

b) Distributively

c) Semi-conservatively

d) Dispersively

Q.18- Telomerase does which of the following-

a) Joins Okazaki fragments on the lagging strand

b) Catalyzes DNA replication at the ends of chromosome

c) Enhances transcription

d) Requires dCTP

Q.19-Eukaryotic RNA polymerase I is specialized to transcribe which of the following?

a)  mRNA

b) tRNA

c) Ribosomal RNA

d) Mitochondrial RNA

Q.20-The melting temperature of DNA is the temperature where:

a) DNA anneals to RNA

b) DNA denatures into single strands

c) DNA is degraded

d) RNA binds to the ribosome

Q.21- Actinomycin D is an inhibitor of-                                                                 

a) Replication                                                                                    

b) Transcription

c) Translation                                                                                    

d) all of the above.

Q.22- In protein synthesis which out of the following is not a termination codon?

a) UAG                                               

b) UGA

c) UUU                                                 

d) UAA                

Q.23- A promoter site on DNA -

a) is present upstream to the start site                 

b) is present on the coding strand           

c) Initiates transcription

d) All of the above          

Q.24- All are true for DNA polymerase except one-

a) Has exonuclease activity

b) Works only in 5`to 3` direction

c) Edits as it synthesizes

d) Synthesizes RNA primer to initiate DNA synthesis.     

Q.25- Which of the following result is provided by Western Blot Analysis

a) Detects DNA molecules                          

b) Detects Protein molecules                    

c) Detects RNA molecules

d) Determines chromosomal structure

Q.26- Which of the following is an anticancer drug?

a) 5- methyl thymidine                 

b) Ribose phosphate                                     

c) Ara C

d) PRPP (5- phosphoribosylpyrophosphate)

Q.27- A 10-year-old Caucasian girl is brought in by her parents for evaluation of a skin disorder. The child has many freckles on her face, arms, and legs. The parents were told by previous physicians that she suffers from Xeroderma pigmentosum and that they should limit her exposure to sun light. What is the most likely etiology of this disorder?

a) Deficient DNA replication

b)  Impaired DNA repair by nucleotide excision

c) Defective RNA transcription from TATA-less promoter

d)  Impaired DNA repair by photo reactivation                                   

Q.28- Which of the following events would occur at the E. coli lac operon when the glucose concentration of the growth medium is low and the lactose concentration is high?

a)  The lac repressor protein will bind to the operator sequence.

b) Ribosomes will stall during translation of the first 13 amino acids.

c) The transcribed RNA will form a cAMP-dependent stem-loop structure to terminate transcription.

d) The catabolite gene activator protein (CAP), bound with cAMP, will stimulate binding of RNA polymerase to the promoter.                                                                          

Q.29- BRCA-1 is associated with which cancer?

a) Breast                                                                             

b) Nerve             

c) Thyroid                                                           

d) Leukemia                      

Q.30- The p53 protein normally promotes

a) DNA replication                                                                          

b) Cell division

c) Tumor formation                                                                        

d) Apoptosis                     

Q.31- What is added to the 3′-end of many eukaryotic mRNAs after transcription?

a) Introns

b) Cap of modified G nucleotide

c) Poly A tail

d) Trinucleotide CCA      

Q.32-The binding of the prokaryotic DNA dependent RNA polymerase to promoter site is inhibited by-

a) Streptomycin                                               

b) Puromycin    

c) Rifampicin                                     

d) Tetracycline                 

 Q.33-The mutagenicity of a compound can be detected by-

a) ELISA                                                                               

b) Ame’s test                                                                    

c) Western blotting

d) Any of the above.     

Q.34- A 20 year old man was diagnosed with abnormal form of β – globin (Hemoglobin Constant Spring) which is longer than the normal protein, which of the following point mutation is consistent with the abnormality?

a) UAA——->CAA                                                       

b) CGA——>UGA                                                        

c) UAA——->UAG

d) GAC——-> UAC

Q.35- Which of the following sugar is found in RNA?

a) 2- deoxy Ribose                                          

b) 3-deoxy Ribose                                          

c) D- Ribose

d) D- Xylulose

Q.36-All are nucleosides except-

a) Cytosine                                                        

b) Guanosine                                                    

c) Inosine

d) Adenosine    

Q.37- What is added to the 3′-end of many eukaryotic tRNAs after transcription?

a)Introns                                                                         

b) Cap of modified G nucleotide

c) Poly A tail

d) Trinucleotide CCA

Q.38-Restriction endonucleases are enzymes –

a) Used for joining DNA to cloning vector             

b) That cleave randomly                                              

c) That digest DNA from ends

d) Cleave DNA at specific sites

Q.39- An 8 –year-old boy is treated with Ciprofloxacin for some respiratory infection. Which of the following enzyme activity is most directly affected by this drug?

a) DNA polymerase                                                        

b) Topo Isomerase                                                         

c) Reverse transcriptase

d) RNA polymerase        

Q.40-Which one of the following molecules is not a component of the 30 S initiation complex?

a) GTP                                                                                  

b) m RNA                                                                            

c) Initiation factor 2

d) ATP                                                  

Q.41- Out of the following, one class of RNA characteristically contains unusual purines and pyrimidines. This RNA is-

a) tRNA                                                                               

b) rRNA                                                                               

c) m RNA

d) 16s RNA                                         

   

 

Key to Answers-

1-d,        2-c,         3-b,        4-b,        5-b,        6-c,         7-a,        8-d,        9-b         10-a,      11-a,     

 

12-a,      13-d,      14-d,      15-c,      16-d,      17-c,      18-b,      19-c,      20-b,      21-b,      22-c,      23-d,

 

24-d,      25-b,      26-c,      27-b,      28-d,      29-a,      30-d,      31-c,      32-c,      33-b,      34-a,      35-c

 

36-a,      37-d,      38-d,      39-b,      40-d,      41-a.

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