Prove that increasing the number of heart chambers increases the level of the animal’s body.

The heart is an organ that consists of muscle cavities. Due to its structure, the heart contracts and blood flows to all organs. Dividing the heart into chambers helps the blood to bring as much oxygen as possible to the organs. Fish have a two-chambered heart, it is a primitive organ, and therefore the brain of fish receives little oxygen. The three-chambered heart appeared in reptiles, it is already more perfect, but the blood – venous and arterial – still mix. In mammals, the heart is already four-chambered, the blood does not mix, so all organs receive a lot of oxygen.