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Author Question: The second demographic transition theory explains that as societies become more prosperous, couples ... (Read 1591 times) |
The familiar sounds of your heart are made by the heart's valves as they open and close.
The lipid bilayer is made of phospholipids. They are arranged in a double layer because one of their ends is attracted to water while the other is repelled by water.
The human body produces and destroys 15 million blood cells every second.
Drugs are in development that may cure asthma and hay fever once and for all. They target leukotrienes, which are known to cause tightening of the air passages in the lungs and increase mucus productions in nasal passages.
Chronic marijuana use can damage the white blood cells and reduce the immune system's ability to respond to disease by as much as 40%. Without a strong immune system, the body is vulnerable to all kinds of degenerative and infectious diseases.