Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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A.
Measurement methods cannot introduce systematic error
B.
Bias is a systematic error in selection, measurement or analysis that can distort an estimated association
C.
Random error and bias are identical
D.
Bias is eliminated automatically by a large sample
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Correct Answer: B. Bias is a systematic error in selection, measurement or analysis that can distort an estimated association
Explanation:
Larger samples reduce random error but do not necessarily correct systematic design or measurement problems.
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A.
Cytokines cannot influence cell differentiation
B.
Specific lymphocytes activate without any signal
C.
Co-stimulation is irrelevant to immune tolerance
D.
Antigen recognition plus appropriate co-stimulation and cytokine signals shape lymphocyte activation and differentiation
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Correct Answer: D. Antigen recognition plus appropriate co-stimulation and cytokine signals shape lymphocyte activation and differentiation
Explanation:
Adaptive responses integrate receptor specificity with co-stimulatory and environmental signals.
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A.
Resistance has no genetic basis
B.
Antibiotic exposure can select resistant organisms already carrying or acquiring resistance determinants
C.
Antibiotics deliberately teach each bacterium to resist
D.
Stopping all infection control prevents resistance
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Correct Answer: B. Antibiotic exposure can select resistant organisms already carrying or acquiring resistance determinants
Explanation:
Selection favours resistant variants, while transmission and gene exchange can spread resistance.
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A.
A reversible competitive antagonist shifts an agonist concentration-response curve to the right without reducing maximal response when enough agonist is available
B.
A competitive antagonist increases agonist potency by shifting the concentration-response curve left while leaving receptor occupancy unchanged
C.
A reversible competitive antagonist necessarily lowers the maximal response even when much higher agonist concentrations are available
D.
An irreversible antagonist permanently occupies receptors, so increasing agonist concentration fully restores the original maximal response
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Correct Answer: A. A reversible competitive antagonist shifts an agonist concentration-response curve to the right without reducing maximal response when enough agonist is available
Explanation:
Competition at the same receptor can be overcome by higher agonist concentration, reducing apparent potency but not efficacy.
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A.
Clearance has no relationship to elimination
B.
Maintenance dosing depends only on tablet colour
C.
Clearance relates elimination rate to drug concentration and helps determine maintenance dosing
D.
Clearance is the same as absorption fraction
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Correct Answer: C. Clearance relates elimination rate to drug concentration and helps determine maintenance dosing
Explanation:
Systemic clearance describes the effective volume cleared per unit time and links concentration to elimination rate.
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A.
Tumours are unrelated to selection among cell clones
B.
A single mutation always produces invasive cancer immediately
C.
DNA repair has no relevance to cancer risk
D.
Cancer develops through accumulated alterations affecting growth control, survival, repair and the tissue environment
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Correct Answer: D. Cancer develops through accumulated alterations affecting growth control, survival, repair and the tissue environment
Explanation:
Tumorigenesis is multistep and reflects genetic, epigenetic and microenvironmental selection.
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A.
Acute inflammation never recruits leukocytes
B.
Inflammatory mediators coordinate vascular change, leukocyte recruitment and local symptoms
C.
All mediators have identical effects
D.
Inflammation occurs without signalling molecules
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Correct Answer: B. Inflammatory mediators coordinate vascular change, leukocyte recruitment and local symptoms
Explanation:
Multiple mediators act on vessels, cells and tissues to produce the organised inflammatory response.
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A.
Compensation always overshoots to the opposite pH disorder
B.
The kidneys cannot affect acid-base balance
C.
The lungs regulate bicarbonate directly as their main action
D.
Compensation changes the other component of the bicarbonate-carbon dioxide system but does not remove the primary disorder
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Correct Answer: D. Compensation changes the other component of the bicarbonate-carbon dioxide system but does not remove the primary disorder
Explanation:
Respiratory and renal responses limit pH change while the primary process remains identifiable.
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A.
Afterload can never influence ejection
B.
Cardiac output equals heart rate multiplied by stroke volume and changes with preload, contractility and afterload
C.
Stroke volume is unrelated to venous return
D.
Cardiac output equals blood pressure divided by temperature
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Correct Answer: B. Cardiac output equals heart rate multiplied by stroke volume and changes with preload, contractility and afterload
Explanation:
Cardiac output integrates rate and stroke volume, while loading conditions and contractility influence stroke volume.
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A.
Transport proteins cannot be selective
B.
All membrane transport directly hydrolyses ATP
C.
Net passive transport follows an electrochemical gradient and does not directly consume ATP
D.
Diffusion moves every solute against its gradient
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Correct Answer: C. Net passive transport follows an electrochemical gradient and does not directly consume ATP
Explanation:
Passive transport is driven by concentration and electrical gradients, although channels or carriers may facilitate it.
Choose an option to check your answer.
A.
Measurement methods cannot introduce systematic error
B.
Bias is a systematic error in selection, measurement or analysis that can distort an estimated association
C.
Random error and bias are identical
D.
Bias is eliminated automatically by a large sample
Show Answer
Correct Answer: B. Bias is a systematic error in selection, measurement or analysis that can distort an estimated association
Explanation:
Larger samples reduce random error but do not necessarily correct systematic design or measurement problems.
Choose an option to check your answer.
A.
Specific lymphocytes activate without any signal
B.
Co-stimulation is irrelevant to immune tolerance
C.
Antigen recognition plus appropriate co-stimulation and cytokine signals shape lymphocyte activation and differentiation
D.
Cytokines cannot influence cell differentiation
Show Answer
Correct Answer: C. Antigen recognition plus appropriate co-stimulation and cytokine signals shape lymphocyte activation and differentiation
Explanation:
Adaptive responses integrate receptor specificity with co-stimulatory and environmental signals.
