Answer and Explanation:
Macros are macronutrients. Your body needs these nutrients in larger amounts in order to function properly as macro means large. In addition, all of these nutrients provide your body with energy measured in the form of calories or kcals. There are three types of macronutrients: carbohydrates, proteins, and fats. But in this case the answer is protein.
Answer:
The baby starts breathing
Explanation:
While in the womb, a fetus has its oxygen delivered to it, and the waste products removed (all via the mother's bloodstream), so there is no reason to separate all the chambers of the heart while still in the womb.
However, once the baby is born and it is breathing, the chambers need to differentiate in order to allow the blood to reach the lungs, and the oxygenated blood and deoxygenated blood do not mix.