OECD guidelines for animal experimentation MCQs With Answer

OECD guidelines for animal experimentation MCQs With Answer is a focused, practical resource for B.Pharm students studying pharmacology, toxicology and preclinical safety. These OECD Test Guidelines and GLP (Good Laboratory Practice) principles define standardized toxicity testing methods, study design, dosing strategies, endpoints, data reporting, and regulatory compliance. Key keywords include OECD Test Guidelines, GLP, 3Rs (replacement, reduction, refinement), acute and repeated dose toxicity, genotoxicity, study director, quality assurance, humane endpoints, and test guideline selection. A clear grasp of these topics helps you design robust animal studies, interpret safety data, and meet ethical and regulatory expectations. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary purpose of OECD Test Guidelines for animal experiments?

• To provide flexible suggestions without standardization
• To standardize methods for toxicity testing and ensure regulatory acceptance
• To replace national regulations entirely
• To limit preclinical testing to in vitro only

Correct Answer: To standardize methods for toxicity testing and ensure regulatory acceptance

Q2. What do the “3Rs” in animal experimentation stand for?

• Reduction, Repetition, Review
• Replacement, Replication, Refinement
• Replacement, Reduction, Refinement
• Refinement, Recording, Responsibility

Correct Answer: Replacement, Reduction, Refinement

Q3. Which statement best describes the role of GLP (Good Laboratory Practice)?

• GLP provides ethical approval for animal use
• GLP ensures data quality, traceability, and reproducibility in non-clinical studies
• GLP only applies to clinical trials
• GLP defines specific dose levels for all studies

Correct Answer: GLP ensures data quality, traceability, and reproducibility in non-clinical studies

Q4. Who is the Study Director under GLP?

• The person responsible for animal care only
• The individual responsible for the overall conduct and integrity of the study
• The laboratory technician recording data
• The member of the ethical committee

Correct Answer: The individual responsible for the overall conduct and integrity of the study

Q5. What is the main function of the Quality Assurance Unit (QAU) in GLP studies?

• To design the study protocol
• To perform statistical analysis of results
• To conduct independent audits and ensure compliance with GLP
• To handle animal procurement only

Correct Answer: To conduct independent audits and ensure compliance with GLP

Q6. Which OECD Test Guidelines are commonly used as alternatives to determine acute oral toxicity without performing an LD50 study?

• TG 408 and TG 414
• TG 420, TG 423 and TG 425
• TG 471 and TG 476
• TG 439 and TG 490

Correct Answer: TG 420, TG 423 and TG 425

Q7. Which OECD Test Guideline covers the bacterial reverse mutation test (Ames test)?

• TG 408
• TG 471
• TG 439
• TG 414

Correct Answer: TG 471

Q8. What is the purpose of a “limit test” in acute toxicity testing?

• To test all possible doses
• To confirm toxicity at very low doses
• To determine absence of significant toxicity at a predefined high dose
• To replace chronic toxicity studies

Correct Answer: To determine absence of significant toxicity at a predefined high dose

Q9. Which items are essential components of raw data archives under GLP?

• Only the final report and photos
• Original observations, SOPs, instrument printouts and the final report
• Only electronic summaries
• Only animal procurement invoices

Correct Answer: Original observations, SOPs, instrument printouts and the final report

Q10. In OECD terminology, what is an “endpoint”?

• A regulatory agency that approves studies
• A measurable biological response or observation used to assess effect
• The person who administers the dose
• The housing facility for animals

Correct Answer: A measurable biological response or observation used to assess effect

Q11. What defines a humane endpoint in an animal study?

• Any time the study director feels like stopping
• Predetermined criteria to minimize pain and distress by terminating or altering the study
• Waiting until animals die to record lethality
• Only removing animals after the study ends

Correct Answer: Predetermined criteria to minimize pain and distress by terminating or altering the study

Q12. Why are in vitro OECD test methods (e.g., reconstructed human tissue tests) important?

• They are always cheaper than in vivo tests
• They help reduce animal use and can provide mechanistic or screening information
• They eliminate the need for reporting
• They replace all GLP requirements

Correct Answer: They help reduce animal use and can provide mechanistic or screening information

Q13. What is the objective of a range-finding (pilot) study?

• To produce the final regulatory report
• To determine suitable dose levels and observe acute effects for the main study
• To train technicians only
• To validate laboratory equipment calibration

Correct Answer: To determine suitable dose levels and observe acute effects for the main study

Q14. In genotoxicity assays, why is a positive control used?

• To show that the test system can detect a known positive response, confirming assay sensitivity
• To increase variability
• To replace negative controls
• To test animal welfare parameters

Correct Answer: To show that the test system can detect a known positive response, confirming assay sensitivity

Q15. Which of the following best exemplifies the “reduction” principle of the 3Rs?

• Replacing an animal test with an in vitro assay
• Refining surgical technique to reduce pain
• Using statistical design to minimize animal numbers while preserving power
• Improving housing enrichment

Correct Answer: Using statistical design to minimize animal numbers while preserving power

Q16. Under GLP, what must be done with study raw data and records?

• They may be discarded after publication
• They must be documented, retained securely and be retrievable for review
• Only summaries are required
• They should be kept only digitally without backups

Correct Answer: They must be documented, retained securely and be retrievable for review

Q17. What is the main difference between OECD TG 421 and TG 422?

• TG 421 is clinical, TG 422 is non-clinical
• TG 421 is a reproduction/developmental screening test; TG 422 combines repeated dose toxicity with reproduction/developmental screening
• TG 421 uses in vitro methods only
• TG 422 is only for genotoxicity

Correct Answer: TG 421 is a reproduction/developmental screening test; TG 422 combines repeated dose toxicity with reproduction/developmental screening

Q18. What should a study protocol include?

• Only the names of the personnel
• Objectives, study design, methods, dose selection, endpoints and statistical plan
• Only the final conclusions
• Only the budget and timelines

Correct Answer: Objectives, study design, methods, dose selection, endpoints and statistical plan

Q19. What is the role of an Institutional Animal Care and Use Committee (IACUC) or equivalent ethical review body?

• To perform all laboratory assays
• To review, approve, and monitor animal use protocols to ensure ethical treatment
• To market the test substance
• To replace GLP requirements

Correct Answer: To review, approve, and monitor animal use protocols to ensure ethical treatment

Q20. Why is proper characterization of the test substance critical in OECD studies?

• Because identity, purity and stability affect study interpretation and reproducibility
• Because it reduces the need for controls
• Because it shortens study duration
• Because it determines animal housing

Correct Answer: Because identity, purity and stability affect study interpretation and reproducibility

Q21. Which approach has largely replaced the traditional LD50 test for acute toxicity assessment?

• Chronic toxicity testing
• The up-and-down procedure and fixed-dose/acute toxic class methods
• Long-term carcinogenicity studies
• Only in vitro cell culture methods

Correct Answer: The up-and-down procedure and fixed-dose/acute toxic class methods

Q22. When is a recovery period included in a repeated dose toxicity study?

• To assess reversibility, persistence or delayed occurrence of toxic effects after treatment stops
• Only to house animals more comfortably
• To extend the study indefinitely
• Only for genotoxicity assays

Correct Answer: To assess reversibility, persistence or delayed occurrence of toxic effects after treatment stops

Q23. Dose level selection for a non-clinical toxicity study is typically based on which of the following?

• Random choice by the technician
• Range-finding data, prior information, and intended margin of safety
• Only the solubility of the vehicle
• Regulatory fees

Correct Answer: Range-finding data, prior information, and intended margin of safety

Q24. What does MTD (maximum tolerated dose) represent in toxicity studies?

• The highest dose that does not cause any observable effect
• The highest dose that produces acceptable toxicity without causing excessive mortality
• The dose used in clinical trials
• The lowest dose that shows therapeutic effect

Correct Answer: The highest dose that produces acceptable toxicity without causing excessive mortality

Q25. Which OECD Test Guideline addresses 90-day repeated dose oral toxicity in rodents?

• TG 408
• TG 471
• TG 420
• TG 439

Correct Answer: TG 408

Q26. Which OECD guideline is used for prenatal developmental toxicity studies?

• TG 408
• TG 414
• TG 471
• TG 420

Correct Answer: TG 414

Q27. What is the benchmark dose (BMD) approach?

• A method to determine the highest dose animals can tolerate
• Statistical dose-response modeling to estimate a dose associated with a specified change in response rate
• A way to benchmark laboratory performance
• A replacement for all in vivo studies

Correct Answer: Statistical dose-response modeling to estimate a dose associated with a specified change in response rate

Q28. How does poor animal welfare affect scientific data quality?

• It only affects animal behavior, not data
• Stress and pain can alter physiology, increasing variability and potentially biasing results
• It makes data collection faster
• Welfare has no impact if GLP is followed

Correct Answer: Stress and pain can alter physiology, increasing variability and potentially biasing results

Q29. Why are Standard Operating Procedures (SOPs) required in GLP studies?

• To document consistent, validated procedures that ensure reproducibility and compliance
• To limit staff training
• To provide templates for final reports only
• To increase study costs deliberately

Correct Answer: To document consistent, validated procedures that ensure reproducibility and compliance

Q30. Which information must always be included in a GLP final study report?

• Only the study title and author names
• Methods, results, discussion, conclusions, and reference to raw data and QA records
• Only the summary tables
• Only statistical p-values

Correct Answer: Methods, results, discussion, conclusions, and reference to raw data and QA records

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