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Author Question: Which of the following is true of active transport mechanisms? A) They are exclusively responsible ... (Read 58 times) |
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
About 600,000 particles of skin are shed every hour by each human. If you live to age 70 years, you have shed 105 pounds of dead skin.
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.
There are 20 feet of blood vessels in each square inch of human skin.
Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.