What similarity do laboratory animals and humans share according to the material?

• A. Organs & Body Systems
• B. Genetic similarity
• C. Hormonal responses
• D. Metabolic pathways

Answer: (A)

The main idea is that mammals share a common body plan with the same major organ systems, and that structural and functional similarity of these systems allows lab animals to model human physiology. Humans and common lab animals have the same cardiovascular, respiratory, digestive, nervous, endocrine, renal, and other organ systems arranged in essentially the same way, with comparable roles in maintaining homeostasis. This shared organization is what makes experiments in animals relevant to human biology, disease, and drug effects, because the basic functions of these systems are conserved across species. While there is genetic similarity and some overlap in hormonal responses and metabolic pathways, those aspects can vary more between species, so the broad, consistent similarity of organs and body systems is the most reliable basis for translation.