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Tomorrow’s Entry Card. Be ready to write the answers to these without any notes. 1. Write out the 3 ideas of the cell theory. 2. How did the microscope make the cell theory possible?. How Was the Cell Theory Developed. And what is it?. and best of all, the unknown, busy, very small
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Tomorrow’s Entry Card Be ready to write the answers to these without any notes. 1. Write out the 3 ideas of the cell theory. 2. How did the microscope make the cell theory possible?
How Was the Cell Theory Developed And what is it?
and best of all, the unknown, busy, very small bugs that swim and bump and hop inside a simple water drop. Impossible! Most Dutchmen said. This Anton's crazy in the head. We ought to ship him off to Spain. He says he's seen a housefly's brain. He says the water that we drink Is full of bugs. He's mad, we think! They called him dumkopf, which means dope. That's how we got the microscope. Maxine Kumin The Microscope Anton Leeuwenhoek was Dutch. He sold pincushions, cloth, and such. The waiting townsfolk fumed and fussed As Anton's dry goods gathered dust. He worked, instead of tending store, At grinding special lenses for A microscope. Some of the things He looked at were: mosquitoes' wings, the hairs of sheep, the legs of lice, the skin of people, dogs, and mice; ox eyes, spiders' spinning gear, fishes' scales, a little smear of his own blood,
Anton von Leeuwenhoek • Dutch tradesman 1632-1723 • He ran a store; microscopes were his hobby. • He discovered bacteria, blood cells and sperm. • He discovered that one drop of water could have thousands of invisible living cells.
“an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. The biggest sort. . . bent their body into curves in going forwards. . . Moreover, the other animalcules were in such enormous numbers, that all the water. . . seemed to be alive.” Discovery of bacteria - In the mouth of old man who had never brushed his teeth Anton von Leeuwenhoek
Von Leeuwenhoek • Studied pondwater, sour milk, and semen • named moving organisms “animalcules” • scared people and caused a sensation
Von Leeuwenhoek’s drawings of “animalcules” set off a flurry of amateur and sometimes ridiculous claims, such as: - pondwater animalcules causing madness!
and... Human sperm cells contain tiny human beings! Today we can look back and think “crazy,” but at the time people took these ideas very seriously.
A Brief History of Cell Study • Robert Hooke (1635-1708) • Invented springs and other parts that made possible the first wrist watches • Studied the motion of the planets • Made a microscope and published a book Micrographia, with drawings of things he saw under his microscope
A Brief History of Cell Study • Robert Hooke looked at pieces of cork under his microscope. • He thought that the shapes looked like (prison) cells
The Cell Theory The cell theory has three parts: • All living things contain at least one cell • Cells are the basic building blocks of all living things, and carry on all life processes. • Cells can only come from pre-existing cells
The cell theory-a closer look • All living things contain at least one cell • Many scientists working after Hooke and Leeuwenhoek observed different plants and animals • Each of them noted that no matter what they observed, if it was alive it had cells.
The cell theory-a closer look • Cells are the basic building blocks of all living things, and carry on all life processes. • scientists quickly realized that when cells were dissected or broken open they died • This meant that whatever “life” is, it is something that happens inside cells
The cell theory-a closer look • Cells can only come from pre-existing cells • does not answer the question of where the first cell came from or how it came to be. • has not been proven wrong yet- no scientist has ever built a living cell from nonliving organic molecules
To summarize - Cell Theory • Cells are the basic units of structure in all living things, and carry on all life processes. • New cells arise only from other living cells. • All organisms are made of one or more cells. • THE MICROSCOPE MADE THE CELL THEORY POSSIBLE!