Alternative and replacement methods to animal toxicity testing MCQs With Answer

Introduction: Alternative and replacement methods to animal toxicity testing are essential topics for M.Pharm students, focusing on scientific, ethical and regulatory shifts that reduce animal use. This collection of MCQs covers in vitro systems (cell lines, primary cultures, organoids, reconstructed tissues), in silico approaches (QSAR, PBPK, read-across), organ-on-chip and microphysiological systems, validated assays (BCOP, HET-CAM, DPRA), omics and AOP frameworks, regulatory validation and IATA concepts. These questions are designed to deepen understanding of methodology, validation criteria, predictive capacity and real-world application in drug safety assessment, preparing students for both exams and research roles in modern toxicology.

Q1. Which of the 3Rs primarily focuses on substituting animals with non-animal techniques for toxicity testing?

• Reduction
• Replacement
• Refinement
• Reassessment

Correct Answer: Replacement

Q2. Which European center is primarily responsible for the scientific validation of alternative methods to animal testing?

• OECD
• FDA
• ECVAM
• ICH

Correct Answer: ECVAM

Q3. An organ-on-chip platform is best described as which of the following?

• A computerized database of organ toxicity data
• A microfluidic device containing living cells that mimics organ-level physiology
• A 2D monolayer cell culture used for genotoxicity testing
• A chemical library screening instrument

Correct Answer: A microfluidic device containing living cells that mimics organ-level physiology

Q4. QSAR models are primarily used to predict toxicity based on which information?

• Animal behavioral responses
• Chemical structure and physicochemical properties
• Clinical adverse event reports
• Histopathological images

Correct Answer: Chemical structure and physicochemical properties

Q5. Which validated in vitro model is commonly used as an alternative to animal tests for skin irritation?

• HepG2 liver spheroids
• Reconstructed human epidermis models (e.g., EpiDerm)
• Mouse fibroblast scratch assay
• Bacterial reverse mutation assay

Correct Answer: Reconstructed human epidermis models (e.g., EpiDerm)

Q6. The BCOP assay evaluates ocular irritation using which biological material?

• Isolated bovine corneas
• Human skin equivalents
• Rat eye in vivo model
• Chick embryo membrane

Correct Answer: Isolated bovine corneas

Q7. The HET-CAM assay is an alternative test that uses which structure to assess irritation?

• Human reconstructed cornea
• Chorioallantoic membrane of a fertilized chicken egg
• Fish embryo chorion
• Porcine skin explant

Correct Answer: Chorioallantoic membrane of a fertilized chicken egg

Q8. Which non-animal assay is widely used to detect mutagenicity of chemicals using bacteria?

• Ames test (bacterial reverse mutation assay)
• DPRA (Direct Peptide Reactivity Assay)
• BCOP
• HET-CAM

Correct Answer: Ames test (bacterial reverse mutation assay)

Q9. The OECD test guideline 236 describes which embryo-based alternative to adult fish toxicity tests?

• Zebrafish adult OECD acute test
• Fish Embryo Toxicity (FET) test
• Chick embryo teratogenicity assay
• Frog embryo limb regeneration assay

Correct Answer: Fish Embryo Toxicity (FET) test

Q10. PBPK modeling is most useful for which purpose in alternative toxicology approaches?

• Predicting in vivo absorption, distribution, metabolism and excretion from in vitro data
• Replacing histopathology assessments
• Measuring direct cytotoxicity in cell culture
• Sequencing genomes of test species

Correct Answer: Predicting in vivo absorption, distribution, metabolism and excretion from in vitro data

Q11. The Adverse Outcome Pathway (AOP) concept links which of the following elements to predict adverse effects?

• Clinical symptoms directly to patient history
• Molecular initiating event through key events to the adverse outcome
• Animal bioassay endpoints to regulatory limits
• In silico predictions to batch release criteria

Correct Answer: Molecular initiating event through key events to the adverse outcome

Q12. Integrated Approaches to Testing and Assessment (IATA) are best described as:

• Single definitive in vitro tests that replace all animal studies
• Frameworks that combine multiple evidence streams to inform safety decisions
• Databases of animal toxicology reports only
• Standard operating procedures for animal care

Correct Answer: Frameworks that combine multiple evidence streams to inform safety decisions

Q13. Which omics technology is specifically useful for identifying transcriptional biomarkers of toxicity?

• Metabolomics
• Proteomics
• Transcriptomics (toxicogenomics)
• Histopathology

Correct Answer: Transcriptomics (toxicogenomics)

Q14. A primary advantage of microphysiological systems (MPS) over traditional 2D cultures is:

• Lower initial setup cost than 2D plates
• Ability to model dynamic cell–cell and cell–matrix interactions under flow conditions
• Faster regulatory acceptance than any other method
• Requirement for fewer technical skills to operate

Correct Answer: Ability to model dynamic cell–cell and cell–matrix interactions under flow conditions

Q15. The Threshold of Toxicological Concern (TTC) approach is applied when:

• High-dose animal data are available for a chemical
• Exposure is negligible and only structural class-based hazard assessment is feasible
• Clinical trial safety data are conclusive
• Only in vitro assays show no effect

Correct Answer: Exposure is negligible and only structural class-based hazard assessment is feasible

Q16. The Direct Peptide Reactivity Assay (DPRA) is an in chemico method used to assess:

• Skin sensitization potential by measuring peptide reactivity
• Cytotoxicity in liver cells
• Ocular penetration of chemicals
• Developmental toxicity in embryos

Correct Answer: Skin sensitization potential by measuring peptide reactivity

Q17. Which of the following is NOT a standard validation criterion for an alternative test method?

• Reproducibility
• Predictive capacity
• Scientific relevance
• In vivo discomfort level

Correct Answer: In vivo discomfort level

Q18. Organoids used in toxicology are best defined as:

• 2D immortalized cell lines grown on plastic
• Three-dimensional, stem cell–derived structures that self-organize and mimic organ features
• Computer simulations of organ function
• Dead tissue sections used for histology

Correct Answer: Three-dimensional, stem cell–derived structures that self-organize and mimic organ features

Q19. The read-across approach predicts toxicity of a target chemical by:

• Direct measurement in a new animal study
• Using toxicity data from structurally similar source chemicals
• Relying solely on high-throughput screening signals without judgment
• Applying default regulatory safety factors only

Correct Answer: Using toxicity data from structurally similar source chemicals

Q20. High-throughput screening (HTS) contributes to alternative testing strategies by:

• Replacing the need for any mechanistic understanding
• Rapidly generating biological activity profiles for large chemical libraries
• Directly measuring whole-animal chronic toxicity endpoints
• Eliminating the need for regulatory review

Correct Answer: Rapidly generating biological activity profiles for large chemical libraries

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