Answer:
The heart has four chambers: The right atrium receives blood from the veins and pumps it to the right ventricle. The right ventricle receives blood from the right atrium and pumps it to the lungs, where it is loaded with oxygen. The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle.
Explanation:
Structurally, DNA and RNA are nearly identical. However, there are three fundamental differences that account for the very different functions of the two molecules. RNA has a ribose sugar instead of deoxyribose sugar like DNA.
Answer:
Cell,tissue, organ, organ system, Organism
Explanation:
because cells make tissues and tissues make organs and many organs make organ systems.