Question

the heart develops in the unborn child, it takes on several distinct appearances, each resembling other animal hearts and each a step higher on the evolutionary ladder. At first, the tube-like heart is much like a fish heart. When it divides into two chambers, it is similar to a frog heart; with three chambers, a snake or turtle heart. Finally, with four chambers, the fully formed heart looks like what it is: the heart of a human being, the most highly evolved mammal

Answer 1

what the question I actually can not understand

Answer 2

Thanks for this knowledge friend