21. Match the drugs in Group I with their mechanism of action in Group II.
    Group I
    P. Paclitaxel
    Q. Colchicine
    R. Etoposide
    S. Methotrexate
    Group II
    1. Inhibits protein translation
    2. Inhibits microtubule depolymerization
    3. Inhibits DNA replication
    4. Alkylates DNA
    5. Inhibits dihydrofolate reductase
    6. Inhibits microtubule polymerization

1. 1. P-1, Q-6, R-3, S-4

   
   
   

   2. P-2, Q-6, R-3, S-5

   
   
   

   3. P-1, Q-3, R-6, S-5

   
   
   

   4. P-2, Q-3, R-6, S-4

   
   
   

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   NA

   Correct Option: B

   NA

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22. A DNA sequence, 5′-A T G G A C G T G C T T C C C A A A G C A T C G G G C –3′, is mutated to obtain
    P. 5′-A T G G A C G T G C T T C a C A A A G C A T C G G G C –3′
    Q. 5′-A T G G A C G T G C T T C C C g A A A G C A T C G G G C –3′
    R. 5′-A T G G A C G T G C T T C C – A A A G C A T C G G G C –3′
    S. 5’-A T G G A  C G
    T G C T T C C C A A t G C A T C G G G C –3′
    T. 5’-A T G G A C G a G C T T C C C A A A G C A T C G G G C –3′
    [Point mutations are shown in the lower case or ‘–’ within the sequences]
    Which of the above mutant sequences DO NOT have frame-shift?

1. 1. P, Q and S

   
   
   

   2. P, S and T

   
   
   

   3. Q, R and S

   
   
   

   4. Q, S and T

   
   
   

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   NA

   Correct Option: B

   NA

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23. Which set of the following events occurs during the elongation step of translation?
    P. Attachment of mRNA with the smaller subunit of ribosome
    Q. Loading of correct aminoacyl-tRNA into the A site
    R. Formation of a peptide bond between the aminoacyl-tRNA in the A site and the peptide chain that is attached to the peptidyl-tRNA in the P site
    S. Dissociation of the ribosomal subunits
    T. Translocation of peptidyl-tRNA from the A site to the P site of the ribosome
    

1. 1. P, Q and R

   
   
   

   2. P, Q and T

   
   
   

   3. Q, R and T

   
   
   

   4. R, S and T

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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24. Based on their function, find the ODD one out.

1. 1. miRNA

   
   
   

   2. siRNA

   
   
   

   3. shRNA

   
   
   

   4. snRNA

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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25. What will be the binding status of regulatory proteins in lac operon when concentrations of both lactose and glucose are very low in the culture medium?

1. 1. Only the repressor remains bound to the operator

   
   
   

   2. Only the cyclic AMP-Catabolic Activator Protein (cAMP-CAP) complex remains bound to the CAP binding site

   
   
   

   3. Neither the repressor nor cAMP-CAP complex remain bound to their respective binding sites

   
   
   

   4. Both the repressor and cAMP-CAP complex remain bound to their respective binding sites

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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