External Gills, Tracheae, and Lungs Share Which Set of Characteristics

question 243

Multiple Choice

External gills, tracheae, and lungs share which set of characteristics?

• A) They are parts of gas exchange systems, they exchange both CO₂ and O₂, and they increase surface area for diffusion.
• B) They are used by water breathers, their functioning is based on countercurrent exchange, and they make use of negative pressure for breathing.
• C) They exchange only O₂, they are associated with a circulatory system, and they are found in vertebrates.
• D) They are found in insects, they employ positive-pressure pumping, and their functioning is based on crosscurrent flow.
• E) They are parts of gas exchange systems, they exchange both CO₂ and O₂, and they decrease surface area for diffusion.

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