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Author Question: Kareem is working on a practical problem with his 16-year-old son, Josh, and his 8-year-old ... (Read 859 times) |
There are 20 feet of blood vessels in each square inch of human skin.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.
The term bacteria was devised in the 19th century by German biologist Ferdinand Cohn. He based it on the Greek word "bakterion" meaning a small rod or staff. Cohn is considered to be the father of modern bacteriology.
IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.