What is the difference between a 3 chambered heart and a 2 chambered heart?

2 chambered - fish, pumps blood in a single circuit, from gill capillaries, tp systemic capillaries, back to heart.
3 chambered - amphibians, turtles, snakes, lizards, has two atria, one undivided ventricle, permits blood diversion away from lungs when diving, but some blood from body & lungs mixes in the ventricle when not diving.

The arrangements of lipids in the membrane makes the cell semi permeable .

In the air and in the lower fre ah water