**Question:** Animal used to demonstrate anaphylaxis in the lab is -

A. Guinea pig
B. Rabbit
C. Rat
D. Mouse

**Correct Answer:** **D. Mouse**

**Core Concept:** Anaphylaxis is a severe, systemic allergic reaction that can be studied in animal models to understand its mechanism, diagnosis, and treatment. It is a critical aspect of medical research, particularly in immunology and allergy.

**Why the Correct Answer is Right:** Mice are widely used in biomedical research due to their similarity to humans in terms of genetic makeup, physiology, and disease susceptibility. Mice have a relatively short life cycle and are easy to breed, maintain, and manipulate genetically. This makes them an ideal model for studying various human diseases, including allergic reactions like anaphylaxis.

**Why Each Wrong Option is Incorrect:**

A. Guinea pig: Guinea pigs have different genetic makeup and physiological characteristics compared to humans, making them less suitable for studying human diseases like anaphylaxis.
B. Rabbit: Rabbits are more prone to spontaneous anaphylaxis, so they are not suitable for demonstrating induced anaphylaxis in the lab.
C. Rat: Rats have different physiological responses to allergens compared to humans, limiting their use in studying anaphylaxis.

**Why Mice are the Best Model:**

Mice have a high degree of homology with human genetic makeup and physiology, making them an appropriate model for studying human diseases. Moreover, their response to allergen exposure is predictable and well-characterized, allowing researchers to study the pathophysiology and treatment of allergic reactions like anaphylaxis.

**Clinical Pearl:** Anaphylaxis is a life-threatening emergency that requires prompt diagnosis and management. Clinical physicians should be familiar with the signs, symptoms, and treatment options for anaphylaxis in human patients. Inducing anaphylaxis in animal models, such as mice, helps researchers better understand the disease mechanisms and develop treatments for human patients.