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Author Question: The day-night cycle is: a. REM sleep b. NREM sleep c. The sleep-wake cycle d. Circadian ... (Read 139 times) |
Blood is approximately twice as thick as water because of the cells and other components found in it.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.
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.