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Author Question: Collagen's molecular structure consists of a. three polypeptide strands twisted together. b. ... (Read 24 times) |
After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.
The familiar sounds of your heart are made by the heart's valves as they open and close.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.
Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.