This concise guide covers common laboratory animals — species, strains, and their applications — tailored for B. Pharm students. It explains key concepts such as laboratory animals, inbred and outbred strains, transgenic and knockout models, and practical uses in pharmacology, toxicology, ADME and drug efficacy testing. The introduction emphasizes strain selection, ethical considerations, welfare practices, and model validity to bridge theory with in vivo study design. Keywords included: laboratory animals, species, strains, applications, animal models, B. Pharm, pharmacology, toxicology, 3Rs, and ethical compliance. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the main advantage of using inbred strains in pharmacological studies?
- Genetic uniformity reducing experimental variability
- Greater genetic variability to mimic human populations
- Lower cost compared to outbred strains
- Higher fertility rates for breeding programs
Correct Answer: Genetic uniformity reducing experimental variability
Q2. Which mouse strain is widely used for immunology research and genetic manipulation?
- C57BL/6
- BALB/c
- Sprague-Dawley
- Wistar
Correct Answer: C57BL/6
Q3. Which of the following is a commonly used outbred rat strain in toxicology and pharmacology?
- Sprague-Dawley
- C57BL/6
- BALB/c
- Nude rat
Correct Answer: Sprague-Dawley
Q4. Which laboratory species lacks the ability to synthesize vitamin C endogenously and is therefore used for nutritional studies?
- Guinea pig
- Mouse
- Rat
- Rabbit
Correct Answer: Guinea pig
Q5. Rabbits are commonly used in preclinical studies for which of the following applications?
- Antibody production and ocular toxicity testing
- Behavioral neuroscience and maze testing
- Inhalation toxicology and cigarette smoke models only
- Transgenic gene knockout studies predominantly
Correct Answer: Antibody production and ocular toxicity testing
Q6. What is a major experimental advantage of zebrafish in pharmacology and developmental biology?
- Transparent embryos and rapid external development
- High phylogenetic similarity to humans in all organs
- Large body size for surgical procedures
- Long lifespan for chronic toxicity studies
Correct Answer: Transparent embryos and rapid external development
Q7. How is a transgenic mouse defined?
- A mouse with an inserted foreign gene integrated into its genome
- A mouse selectively bred for behavioral traits
- An animal raised in specific pathogen-free conditions
- A mouse with naturally occurring spontaneous mutations only
Correct Answer: A mouse with an inserted foreign gene integrated into its genome
Q8. What does SPF stand for in animal facility terminology?
- Specific pathogen-free
- Standard practice facility
- Special physical facility
- Sanitized pathogen-free
Correct Answer: Specific pathogen-free
Q9. Compared to inbred strains, outbred strains are characterized primarily by:
- Greater genetic heterogeneity
- Complete genetic uniformity
- Lower variability in drug response
- Being genetically engineered
Correct Answer: Greater genetic heterogeneity
Q10. What is the primary purpose of a knockout mouse model in biomedical research?
- To inactivate a specific gene to study its function
- To increase expression of a human gene
- To model infectious diseases only
- To provide animals with enhanced fertility
Correct Answer: To inactivate a specific gene to study its function
Q11. The Syrian (golden) hamster cheek pouch is especially used to model which condition?
- Local carcinogenesis and tumor biology
- Renal failure and dialysis procedures
- Long-term behavioral assays for learning
- Transgenic gene expression studies
Correct Answer: Local carcinogenesis and tumor biology
Q12. When selecting an animal model for a drug study, which criterion is most critical for translational relevance?
- Physiological and pharmacological similarity to humans
- Lowest purchase price
- Availability of large colony sizes only
- Ability to perform extensive behavioral tests exclusively
Correct Answer: Physiological and pharmacological similarity to humans
Q13. What defines a xenograft model commonly used in oncology research?
- Implantation of human tumor cells into immunodeficient mice
- Injection of bacterial pathogens into normal mice
- Cross-breeding two inbred mouse strains
- Use of zebrafish embryos to model cancer
Correct Answer: Implantation of human tumor cells into immunodeficient mice
Q14. Why is environmental enrichment provided in laboratory animal housing?
- To improve welfare, reduce stress, and enhance data quality
- To increase metabolic rate artificially
- To reduce the need for veterinary care entirely
- To accelerate breeding cycles only
Correct Answer: To improve welfare, reduce stress, and enhance data quality
Q15. Which route is commonly used for repeatable systemic dosing in rodents during preclinical studies?
- Oral gavage
- Intracerebral injection
- Topical application only
- Intraocular instillation
Correct Answer: Oral gavage
Q16. LD50 in toxicology refers to:
- The dose that kills 50% of a tested population
- The lethal dose for 5% of animals
- The dose causing liver damage in 50% of animals
- The lowest dose that produces any effect
Correct Answer: The dose that kills 50% of a tested population
Q17. Which anaesthetic combination is widely used for surgical procedures in rodents?
- Ketamine and xylazine
- Aspirin and paracetamol
- Penicillin and streptomycin
- Atropine alone
Correct Answer: Ketamine and xylazine
Q18. Which commonly used laboratory rat strain is albino and frequently used in pharmacology?
- Wistar
- C57BL/6
- BALB/c
- Nude rat
Correct Answer: Wistar
Q19. Which immunodeficient mouse strain is classically used for human tumor xenografts due to lack of thymus?
- Nude mouse
- Sprague-Dawley
- Wistar
- BALB/c
Correct Answer: Nude mouse
Q20. Drosophila melanogaster is a powerful laboratory model mainly for:
- Genetic and developmental biology studies
- Large-animal surgical technique development
- In vivo cardiovascular pharmacology
- Ophthalmic toxicity testing
Correct Answer: Genetic and developmental biology studies
Q21. What is an important experimental advantage of using outbred strains in toxicology studies?
- Genetic variability that better represents human population responses
- Absolute genetic uniformity for precise gene studies
- Guaranteed resistance to common pathogens
- Consistent tumor susceptibility across individuals
Correct Answer: Genetic variability that better represents human population responses
Q22. The typical estrous cycle length in rats is approximately:
- 4–5 days
- 1–2 days
- 10–12 days
- 28 days
Correct Answer: 4–5 days
Q23. The 3Rs principle in animal research stands for:
- Replacement, Reduction, Refinement
- Restoration, Reuse, Recycling
- Randomization, Repetition, Replication
- Reduce, Rehome, Rehabilitate
Correct Answer: Replacement, Reduction, Refinement
Q24. Which species is most commonly used for regulatory ophthalmic toxicity and irritation testing?
- Rabbit
- Mouse
- Guinea pig
- Zebrafish
Correct Answer: Rabbit
Q25. Which mouse strain is known to be Th2-biased and commonly used in allergy and antibody-response studies?
- BALB/c
- C57BL/6
- Sprague-Dawley
- Wistar
Correct Answer: BALB/c
Q26. Which laboratory species has historically been preferred for studying bronchoconstriction and allergic airway responses?
- Guinea pig
- Rabbit
- Zebrafish
- Fruit fly
Correct Answer: Guinea pig
Q27. Gnotobiotic animals are best described as:
- Animals with a defined or known microbiota (including germ-free)
- Animals raised under standard, non-sterile conditions
- Wild-caught animals with unknown infections
- Animals genetically modified to have human gut flora only
Correct Answer: Animals with a defined or known microbiota (including germ-free)
Q28. Which behavioral test is commonly used to assess anxiety-like behavior in rodents?
- Elevated plus maze
- Open field forced swim test
- Rotarod endurance test
- T-maze olfactory test
Correct Answer: Elevated plus maze
Q29. Which rat model is widely used to study essential hypertension and cardiovascular pharmacology?
- Spontaneously hypertensive rat (SHR)
- Sprague-Dawley
- Wistar
- Nude rat
Correct Answer: Spontaneously hypertensive rat (SHR)
Q30. For precise small-volume systemic injections in mice, which route is commonly used?
- Intravenous injection via the tail vein
- Oral drop application
- Subcutaneous injection at the scruff only
- Topical skin application
Correct Answer: Intravenous injection via the tail vein
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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