Question

Explain why the a single loop circulatory system is able to supply raw materials to cells as fast as the double – loop circulatory system.

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Answer 1

In the case of single circulatory systems, e.g. as in fish, the heart receives deoxygenated blood (also described as 'oxygen-poor blood') into the atrium of the heart and pumps it through the ventricle of the heart so that it continues onwards to the gills.