Question

there is no double circulation in the following vertebrates a) Amphibians b) mammals c) birds d) fishes​

Answer 1

Answer:

In incomplete double circulation, blood comes to the heart by two different routes but goes out through a single route, and amphibian heart is three chambered left atrium and right atrium and single ventricle. Hence blood oxygenated blood comes through the left atrium and deoxygenated blood comes through right atrium to the heart and goes out a through a single ventricle.