C:-The dose at which 50% of the tested animals exhibit a biological response
D:-The dose at which some animals exhibit a biological response
Correct Answer:- Option-C

Question37:-Match the following drugs with their General targets

Drugs General Targets
^. Rifampicin 1. Act on 30S subunit of ribosome and block the
protein

synthesis
B. Tetracycline ii. Binds to RNA polymerase and interferes
transcription

process
C. Cephalosporins iii. Act on 50S subunit of ribosome and block the
protein

synthesis

D. Erythromycin iv. Inhibit the cell wall synthesis

A:-A-iv, B-ii, C-i, D-iii
B:-A-ii, B-i, C-iv, D-iii
C:-A-ii, B-iii, C-iv, D-i
D:-A-iii, B-iv, C-i, D-ii
Correct Answer:- Option-B
Question38:-Which of the following statement about Cytochrome P450 is false?

A:-Cytochrome P450 (CYP) is a hemeprotein that plays an important role in
drug and xenobiotic metabolism

B:-A fat-free diet increases the Cytochrome P450 level

C:-Phase | reactions of drug metabolism are mainly catalyzed by the
Cytochrome P450

D:-Cytochrome P450 belongs to the class of enzymes called monooxygenase
Correct Answer:- Option-B

Question39:-Which of the following reaction doesn't involve phase II of drug
metabolism

A:-Glucuronidation
B:-Sulfaction
C:-Methylation
D:-Hydroxylation

Correct Answer:- Option-D

Question40:-Match the bacterial toxins with their mode of action

Toxins Mode of action
^. Pertussis toxin i. Inhibit neurotransmitter release in a neuron
B. Diphtheria toxin ii. Selective blockers of acetylcholine release
from nerve
endings
C. Botulinum toxin iii. Inactivates elongation factor (EF-2) and

inhibits