In which of the following animals does blood flow directly from respiratory organs to tissues without first returning to the heart?

Question

Quizplus · Accepted Answer

Fish have a single-loop circulatory system where blood flows directly from the gills (respiratory organ) to the tissues without returning to the heart. This type of circulation is known as a countercurrent exchange system, which maximizes the exchange of oxygen and carbon dioxide.

In Which of the Following Animals Does Blood Flow Directly