Answer:
the process of DNA replication is called semi conservative because it results in two DNAs having a new strand and a old strand which is from the original DNA molecule
The best answer is b. 4
The human heart has four chambers - two atria and two ventricles.
1. Right atrium - receives oxygen-poor blood from the body and pumps it to the right ventricle.
2. Right ventricle - pumps oxygen-poor blood to the heart.
3. Left atrium - receive oxygen - rich blood from the lungs.
4. Left ventricle - pumps oxygen rich blood to the body.
The heart is a muscular organ. It is about the size of a closed fist. It is located in the thoracic cavity. It is protected by the rib cage and is the major organ of the circulatory system.
The left side of the heart collects oxygen-rich blood from the lungs and pumps it to the body. The left and right sides of the heart are divided by walls<span> called septums. There is an atrial septum that separates the right and left atriums, and a ventricular septum that separates the right and left ventricles.</span>
