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Hooked on Biology
The first person to observe cells was Robert Hooke. In 1665, this English scientist used a crude, homemade microscope to study objects like thin pieces of cork. He came up with the word "cell" because the little rectangles he saw reminded him of the small spaces where monks live in a monastery. Two centuries passed before scientists realized the importance of Hooke's observations.
Contains: chromosomes, genes, and DNA
Size: from several feet long to 1/100th the size of the dot above this letter "i"
Made of: water, proteins, fat, sugar, and DNA
Reproduction: before cells divide they make a copy of their DNA, so two new cells have identical copies of the DNA
Why important: makes up all living things
What parts of your body are NOT made of living cells?
hair and nails
muscles and bones
ears and nose
Correct!
Your hair and nails are made up of stuff called protein, not cells. That's why it doesn't hurt when you cut them.
How long are the nerve cells in a giraffe's neck?
about one inch
about one foot
about ten feet
Correct!
Among the largest cells in nature, the nerve cells in a giraffe's neck can be about ten feet long. Boy, is that stretching it!
All cells are round.
Fact
OR
Fiction
?
Fiction
Some cells are round, but they come in many shapes and sizes depending on what they do and where they are. Plant cells, for example, can be rectangular.
Your bones are made of hardened, dead cells.
Fact
OR
Fiction
?
Fiction
Not at all; in fact, they are pretty lively. That's why if you break a bone, it heals in a couple of weeks.