Comparative Physiology MCQs with Answers

Comparative physiology is the science of comparative ability: how different species make similar functions and how those processes have evolved. Thus, comparative physiology can help researchers in their search for physiological adaptations that enable the animals to survive and reproduce under various environments. Indeed, it is especially enlightening to study comparative vertebrate physiology since it reveals commonalties and differences among backboned animals, including fish, amphibians, reptiles, birds, and mammals.

Comparative vertebrate physiology is concerned with how these animals maintain themselves in a homeostatic state, obtain and metabolize nutrients to construct tissues, reproduce, and respond to environmental challenges. For instance, comparative study of the respiratory systems of fish and birds will underline how different vertebrates have adapted to extract oxygen from water and air, respectively. Fish breathe easily in water because they have gills. Birds, on the other hand, possess one of the most elaborately developed systems of respiration-including air sacs and special lung structure to take up oxygen easily at high altitudes.

Some comparative studies extend to cardiovascular, thermoregulatory, and osmoregulatory systems. For example, the comparison of reptilian hearts and mammalian hearts relates to changes with respect to evolutionary history that supports differences in lifestyle and metabolic needs. Reptiles typically have three-chambered hearts that permit a degree of admixture of oxygenated and deoxygenated blood. In contrast, mammals have a four-chambered heart where the separation of the two flows is complete, thus supporting their higher metabolic rates.