What are two advantages of breathing air, compared with obtaining dissolved oxygen from water? What is a comparative disadvantage of breathing air?

Verified step by step guidance

1. Identify the differences in oxygen availability between air and water. Air typically contains a higher concentration of oxygen compared to water, which means organisms that breathe air can take in more oxygen with each breath than those extracting oxygen from water.
2. Consider the energy efficiency of breathing mechanisms. Breathing air generally requires less energy than the process of extracting oxygen from water, making it more energy-efficient for terrestrial organisms.
3. Examine the respiratory adaptations in different environments. Organisms adapted to breathe air have evolved efficient respiratory systems, such as lungs, that are highly effective at gas exchange in air-filled environments.
4. Discuss the limitations of air breathing, such as the necessity of maintaining moist respiratory surfaces. Air-breathing organisms must keep their respiratory surfaces moist to facilitate gas exchange, which can be a challenge in dry environments.
5. Explore the dependency on specific habitats. Air-breathing organisms are generally limited to terrestrial or aerial habitats, whereas organisms that extract oxygen from water can inhabit a variety of aquatic environments.

Key Concepts

Oxygen Availability

Air contains a higher concentration of oxygen compared to water, making it more efficient for organisms to extract the oxygen they need for cellular respiration. This higher availability allows for greater metabolic rates and energy production, which is crucial for sustaining active lifestyles in terrestrial environments.

Respiratory Structures

Terrestrial organisms have evolved specialized respiratory structures, such as lungs, that are adapted for extracting oxygen from air. These structures are typically more efficient than gills, which are designed for extracting dissolved oxygen from water, allowing for more effective gas exchange in a gaseous medium.

Water Loss and Desiccation

Breathing air can lead to increased water loss through evaporation, which is a significant disadvantage for terrestrial organisms. In contrast, aquatic organisms are surrounded by water, reducing the risk of desiccation. This trade-off means that air-breathing animals must have adaptations to conserve water while still meeting their oxygen needs.