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Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
According to research, pregnant women tend to eat more if carrying a baby boy. Male fetuses may secrete a chemical that stimulates their mothers to step up her energy intake.
There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.
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.