[Campbell Biology P.989] A deep-sea hydrothermal vent organism is discovered that relies on ... | Practice Question

A deep-sea hydrothermal vent organism is discovered that relies on dissolved oxygen for respiration, despite living in an environment with extremely low oxygen concentration. Based on the principles of gas exchange described in the text, which of the following adaptations would most likely be observed in this organism's respiratory system?

  • A: Highly convoluted and thin respiratory surfaces with mechanisms to ensure constant, efficient water flow.
  • B: A thick, impermeable body surface with minimal specialized respiratory organs.
  • C: A reduced surface area for gas exchange, relying on increased blood oxygen carrying capacity.
  • D: A respiratory system that minimizes water flow to conserve energy in the harsh environment.

Explanation

To efficiently take up oxygen in a low-concentration environment, an organism needs to maximize the rate of diffusion. This is achieved by increasing the surface area for diffusion highly convoluted/branched gills , shortening the diffusion path thin surfaces , and maintaining a steep concentration gradient by ensuring constant and efficient water flow over the respiratory surface. Options B, C, and D describe adaptations that would hinder or reduce efficient gas exchange, which would be detrimental in a low-oxygen environment.