When the atrioventricular valves open.
This is when Ventricles are being filled with blood from the atrium.
Water molecules bond to each other in a covalent bond where they stay connected. They also have poles like a magnet, making it a polar molecule.
If water is no longer polar the surface tension would lower to the point where ice can no longer float, the water would freeze, cooling the climate considerably.
Adaptive immunity.
When antibodies are produced by lymphocytes, the body is conducting adaptive immunity.
Adaptive immunity is the body's way of identifying the presence of an antigen, recognizing what type of antigen it is, and producing antibodies that are specifically designed to attacked the said antigen.
