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Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.
The average adult has about 21 square feet of skin.
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.
About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.