Introduction to cell injury and adaptation MCQs With Answer

Introduction: This concise, Student-friendly post explains cell injury and adaptation MCQs for B. Pharm students, focusing on mechanisms, examples, and clinical relevance. Learn essential keywords such as cell injury and adaptation MCQs, reversible and irreversible injury, apoptosis, necrosis, oxidative stress, mitochondrial dysfunction, hypertrophy, hyperplasia, metaplasia, and drug-induced toxicity. The material links basic pathology with pharmacology—highlighting how drugs cause or modulate injury, biomarkers, and therapeutic strategies. Designed to build conceptual depth and exam readiness, these practice questions emphasize pathways, morphological changes, and laboratory correlations crucial for pharmacy practice and therapeutics. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which feature best distinguishes apoptosis from necrosis?

• Cell swelling and plasma membrane rupture
• Chromatin condensation and formation of apoptotic bodies
• Inflammatory cell infiltration at the site
• Enzymatic digestion of cytoplasmic organelles with tissue liquefaction

Correct Answer: Chromatin condensation and formation of apoptotic bodies

Q2. The primary early biochemical event in ischemic cell injury is:

• Activation of caspases
• ATP depletion leading to failure of ion pumps
• Massive lipid accumulation in cytoplasm
• Activation of lysosomal hydrolases

Correct Answer: ATP depletion leading to failure of ion pumps

Q3. Which intracellular organelle is most critical in initiating apoptosis via the intrinsic pathway?

• Golgi apparatus
• Mitochondrion
• Endoplasmic reticulum
• Lysosome

Correct Answer: Mitochondrion

Q4. Lipid peroxidation in cell membranes is principally caused by:

• Excess ATP synthesis
• Reactive oxygen species (ROS)
• Elevated intracellular calcium binding to membranes
• Protein ubiquitination

Correct Answer: Reactive oxygen species (ROS)

Q5. A reversible cellular change typically seen early in hypoxic injury is:

• Pyknosis of the nucleus
• Cell swelling with blebbing of the plasma membrane
• Coagulative necrosis
• Autolysis with loss of nuclear staining

Correct Answer: Cell swelling with blebbing of the plasma membrane

Q6. Which enzyme is a sensitive marker of myocardial cell injury used in clinical practice?

• Alanine aminotransferase (ALT)
• Lactate dehydrogenase (LDH)
• Troponin I
• Alkaline phosphatase (ALP)

Correct Answer: Troponin I

Q7. Cellular adaptation defined by an increase in cell size in response to increased workload is called:

• Hyperplasia
• Hypertrophy
• Metaplasia
• Dysplasia

Correct Answer: Hypertrophy

Q8. Barrett’s esophagus is an example of which adaptive change?

• Hypertrophy of squamous epithelium
• Metaplasia from squamous to columnar epithelium
• Hyperplasia of basal cells
• Dysplasia leading directly to carcinoma

Correct Answer: Metaplasia from squamous to columnar epithelium

Q9. Which of the following best describes reperfusion injury?

• Tissue repair following ischemia without ROS involvement
• An exacerbation of injury due to sudden restoration of blood flow and ROS generation
• Purely immune-mediated damage unrelated to ischemia
• A form of metaplasia due to hypoxia

Correct Answer: An exacerbation of injury due to sudden restoration of blood flow and ROS generation

Q10. Which drug overdose causes hepatocellular necrosis via reactive metabolite formation and glutathione depletion?

• Ibuprofen
• Acetaminophen (paracetamol)
• Amoxicillin
• Metformin

Correct Answer: Acetaminophen (paracetamol)

Q11. Which intracellular accumulation often signals chronic cell injury and can impair cell function?

• Glycogen only in skeletal muscle after exercise
• Excessive lipid accumulation (steatosis) in hepatocytes
• Transient calcium uptake during excitation
• Brief metrial swelling in mitochondria

Correct Answer: Excessive lipid accumulation (steatosis) in hepatocytes

Q12. Which molecular event most directly leads to loss of membrane phospholipids in severe cell injury?

• Overactivation of ubiquitin-proteasome system
• Activation of phospholipases due to increased intracellular calcium
• Excessive DNA repair enzyme activity
• Upregulation of heat shock proteins

Correct Answer: Activation of phospholipases due to increased intracellular calcium

Q13. A hallmark morphological change of irreversible cell injury is:

• Cellular swelling that is fully reversible
• Nuclear pyknosis, karyorrhexis, and karyolysis
• Transient ER dilation with polysome detachment
• Increased glycogen stores

Correct Answer: Nuclear pyknosis, karyorrhexis, and karyolysis

Q14. Which caspase group is primarily responsible for execution-phase apoptosis?

• Initiator caspases (e.g., caspase-8, -9)
• Executioner caspases (e.g., caspase-3, -6, -7)
• Inflammatory caspases (e.g., caspase-1)
• DNA repair caspases

Correct Answer: Executioner caspases (e.g., caspase-3, -6, -7)

Q15. Chronic exposure to cigarette smoke causing squamous metaplasia in bronchi is an example of an adaptation that:

• Is always permanent and irreversible
• May be protective but predisposes to dysplasia and cancer
• Does not alter regeneration potential
• Is a form of apoptosis

Correct Answer: May be protective but predisposes to dysplasia and cancer

Q16. Which mediator released from necrotic cells activates inflammation by binding pattern recognition receptors?

• ATP as a DAMP (damage-associated molecular pattern)
• Insulin
• Mitochondrial DNA that acts as a DAMP
• Cytochrome P450 enzymes

Correct Answer: Mitochondrial DNA that acts as a DAMP

Q17. Which type of necrosis is typically seen in ischemic infarcts in solid organs like the kidney?

• Liquefactive necrosis
• Coagulative necrosis
• Caseous necrosis
• Fat necrosis

Correct Answer: Coagulative necrosis

Q18. Endoplasmic reticulum stress leading to unfolded protein response (UPR) can result in:

• Restoration of homeostasis or apoptosis if stress is severe
• Guaranteed cell proliferation
• Immediate necrosis without signaling
• Increased mitochondrial ATP synthesis only

Correct Answer: Restoration of homeostasis or apoptosis if stress is severe

Q19. Which intracellular ion increase is most directly implicated in activating degradative enzymes during cell injury?

• Sodium
• Potassium
• Calcium
• Chloride

Correct Answer: Calcium

Q20. Autophagy is best described as:

• A form of necrosis causing inflammation
• A regulated lysosomal degradation pathway that can be protective under stress
• Uncontrolled protein aggregation without degradation
• A process exclusively leading to apoptosis

Correct Answer: A regulated lysosomal degradation pathway that can be protective under stress

Q21. Which of the following is a common biochemical marker elevated early in hepatic cell necrosis?

• Serum creatinine
• Alanine aminotransferase (ALT)
• Serum amylase only in pancreatitis
• Troponin T

Correct Answer: Alanine aminotransferase (ALT)

Q22. The key event in oxidative stress-mediated cell injury is imbalance between:

• DNA synthesis and repair
• Protein synthesis and degradation
• Reactive oxygen species generation and antioxidant defenses
• Calcium influx and sodium efflux only

Correct Answer: Reactive oxygen species generation and antioxidant defenses

Q23. Which pharmacologic agent can reduce free radical-mediated injury by replenishing glutathione stores in acetaminophen toxicity?

• N-acetylcysteine
• Activated charcoal
• Vitamin K
• Erythropoietin

Correct Answer: N-acetylcysteine

Q24. Which genetic defect would most likely impair apoptosis and predispose to cancer?

• Overexpression of pro-apoptotic BAX protein
• Loss-of-function mutation in p53 tumor suppressor
• Gain-of-function mutation in caspase-3
• Enhanced cytochrome c release from mitochondria

Correct Answer: Loss-of-function mutation in p53 tumor suppressor

Q25. Which pattern of necrosis is characteristically associated with tuberculosis?

• Coagulative necrosis
• Liquefactive necrosis
• Caseous necrosis
• Fat necrosis

Correct Answer: Caseous necrosis

Q26. In drug-induced liver injury, centrilobular (zone 3) hepatocyte necrosis is often due to:

• Higher oxygen tension in zone 1
• Greater expression of cytochrome P450 enzymes and reactive metabolites
• Immunity-mediated bile duct injury only
• Excessive glycogen storage in zone 3

Correct Answer: Greater expression of cytochrome P450 enzymes and reactive metabolites

Q27. Which laboratory test elevation is most specific for acute pancreatic cell injury?

• AST (aspartate aminotransferase)
• Serum amylase and lipase, with lipase more specific
• Alkaline phosphatase
• Troponin I

Correct Answer: Serum amylase and lipase, with lipase more specific

Q28. Which cellular adaptation involves an increase in cell number due to growth factor stimulation?

• Hypertrophy
• Hyperplasia
• Metaplasia
• Aging

Correct Answer: Hyperplasia

Q29. What is the role of heat shock proteins (HSPs) in cell stress?

• They act as chaperones to refold denatured proteins and protect cells
• They directly lyse damaged cells
• They permanently block apoptosis
• They increase ROS production

Correct Answer: They act as chaperones to refold denatured proteins and protect cells

Q30. Lipofuscin pigment accumulation in aging cells indicates:

• Active necrosis
• Previous free radical injury and impaired degradation—“wear-and-tear” pigment
• Acute viral infection
• Elevated mitochondrial biogenesis only

Correct Answer: Previous free radical injury and impaired degradation—“wear-and-tear” pigment

Q31. Which process involves replacement of one differentiated cell type by another better suited to the new stress?

• Dysplasia
• Metaplasia
• Apoptosis
• Necrosis

Correct Answer: Metaplasia

Q32. Which feature is characteristic of coagulative necrosis on histology?

• Preservation of tissue architecture with loss of nuclei
• Complete digestion of tissue with pus formation
• Cheesy-white debris with granulomatous inflammation
• Fatty saponification

Correct Answer: Preservation of tissue architecture with loss of nuclei

Q33. In ischemic injury, mitochondrial permeability transition pore opening leads to:

• Enhanced ATP synthesis
• Loss of mitochondrial membrane potential and ATP depletion
• Immediate restoration of calcium homeostasis
• Decreased ROS formation only

Correct Answer: Loss of mitochondrial membrane potential and ATP depletion

Q34. Which measurement is most useful to monitor rhabdomyolysis-related muscle cell injury?

• Serum amylase
• Creatine kinase (CK), especially CK-MM or CK-total
• ALT only
• Serum bilirubin

Correct Answer: Creatine kinase (CK), especially CK-MM or CK-total

Q35. Which of the following best explains cellular calcification in necrotic tissue?

• Dystrophic calcification occurs in dead or dying tissues with normal serum calcium
• Metastatic calcification only occurs in localized necrosis
• Calcification always indicates systemic hypercalcemia
• Calcification is a reversible adaptive response

Correct Answer: Dystrophic calcification occurs in dead or dying tissues with normal serum calcium

Q36. Which transcription factor is activated by hypoxia and mediates adaptive responses including angiogenesis?

• NF-κB
• HIF-1α (hypoxia-inducible factor 1-alpha)
• p53 exclusively for apoptosis
• c-Jun only in proliferation

Correct Answer: HIF-1α (hypoxia-inducible factor 1-alpha)

Q37. Which cellular adaptation is commonly induced by increased endocrine stimulation, such as in the female breast during pregnancy?

• Atrophy
• Hyperplasia
• Metaplasia
• Irreversible necrosis

Correct Answer: Hyperplasia

Q38. Which free radical-generating reaction is catalyzed by iron via the Fenton reaction?

• Superoxide dismutase producing H2O2
• Conversion of H2O2 to hydroxyl radical (•OH)
• Reduction of glutathione
• Formation of nitric oxide from arginine

Correct Answer: Conversion of H2O2 to hydroxyl radical (•OH)

Q39. A decrease in cell size due to reduced workload or loss of innervation is termed:

• Hypertrophy
• Atrophy
• Hyperplasia
• Metaplasia

Correct Answer: Atrophy

Q40. Which cellular event is a feature of apoptosis detectable by TUNEL assay?

• Membrane rupture with release of intracellular enzymes
• DNA fragmentation with internucleosomal cleavage
• Massive cell swelling only
• Extracellular accumulation of lipids

Correct Answer: DNA fragmentation with internucleosomal cleavage

Q41. In the extrinsic apoptosis pathway, which receptor-ligand interaction is central?

• TNF family receptor binding (e.g., Fas-FasL)
• Insulin receptor activation
• EGF receptor binding causing proliferation
• Integrin-ligand adhesion only

Correct Answer: TNF family receptor binding (e.g., Fas-FasL)

Q42. Which of the following is a common mechanism of drug-induced nephrotoxicity leading to tubular cell injury?

• Excessive hepatic glycogen deposition
• Direct tubular epithelial toxicity and ischemia
• Stimulation of erythropoiesis
• Enhanced bile flow causing cholestasis

Correct Answer: Direct tubular epithelial toxicity and ischemia

Q43. Which morphological change is typical of irreversible mitochondrial damage?

• Mild mitochondrial swelling reversible with reperfusion
• Profound mitochondrial swelling with loss of cristae and rupture
• Transient increase in cristae number
• Complete preservation of structure despite ATP loss

Correct Answer: Profound mitochondrial swelling with loss of cristae and rupture

Q44. Which pattern of cell death often elicits minimal inflammatory response due to rapid phagocytosis?

• Necrosis
• Apoptosis
• Coagulative necrosis with calcification
• Liquefactive necrosis with pus

Correct Answer: Apoptosis

Q45. Chronic inflammation and repeated injury to epithelium increases the risk of progression to:

• Regenerative hyperplasia only
• Dysplasia and eventual neoplasia
• Immediate apoptosis with no long-term effects
• Complete restoration to original tissue without mutation risk

Correct Answer: Dysplasia and eventual neoplasia

Q46. Which event best characterizes fatty change (steatosis) in hepatocytes?

• Increased triglyceride accumulation within cytoplasmic lipid vacuoles
• Excessive protein aggregation in the nucleus
• Mineral deposition in necrotic tissue
• Massive glycogen loss from cells

Correct Answer: Increased triglyceride accumulation within cytoplasmic lipid vacuoles

Q47. Which cellular mechanism is responsible for removal of damaged organelles and long-lived proteins to maintain cell homeostasis?

• Necrosis
• Autophagy-lysosomal pathway
• Glycolysis upregulation only
• Immediate apoptosis without recycling

Correct Answer: Autophagy-lysosomal pathway

Q48. Which of the following is NOT typically an outcome of chronic oxidative stress in tissues?

• Lipid peroxidation and membrane damage
• DNA strand breaks and mutations
• Reversible restoration without any protein modification
• Activation of pro-inflammatory signaling pathways

Correct Answer: Reversible restoration without any protein modification

Q49. In the context of pharmacology, inhibition of mitochondrial complex I can cause cell injury mainly by:

• Increasing ATP production
• Decreasing ROS generation exclusively
• Impairing oxidative phosphorylation leading to ATP depletion
• Stimulating protein synthesis

Correct Answer: Impairing oxidative phosphorylation leading to ATP depletion

Q50. Which cellular adaptation involves both increased cell size and enhanced synthesis of sarcomeric proteins in response to chronic hemodynamic overload?

• Cardiac hypertrophy
• Cardiac hyperplasia
• Cardiac metaplasia
• Cardiac dysplasia

Correct Answer: Cardiac hypertrophy

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