Cell Theory BrainPOP:Cells
Cells were not discovered until the microscope was invented!
I invented the microscope! Robert Hooke In 1665, he was the first scientist to observe cells with a microscope he made. Zacharias Jansen I invented the microscope!
He observed cork (from the dead bark of a tree) under his microscope and saw the cell walls (the cell was no longer living). what he saw cork
Why did he name them cells? Hooke thought the structures he was observing looked like the cells (“small rooms”) where monks lived. So, he named them cells!
Anton van Leeuwenhoek 1670- first person to observe cells that were alive under the microscope. He was looking at microscopic organisms found in pond water!
In the 1830’s two other scientist also contributed to what we know about cells… Matthias Schleiden Theodor Schwann Observed that plants were made of cells. Observed that animals were made of cells.
In 1855, another scientist named Rudolf Virchow proposed the idea that cells come from other cells that already exist.
How do cells come from other cells? They divide!
Through the research of these scientists and many more, the cell theory was developed. A scientific theory is a scientific explanation that is accepted as true and supported by much research and experimentation.
The Cell Theory All living things are composed of cells. Cells are the basic units in living things. All cells are produced from other cells through cell division.
Biotic If something is made of cells, we say that it is biotic. Biotic “life”
Abiotic “without” “life” Abiotic If something is NOT made of cells, we say that it is abiotic. Abiotic “without” “life”
What is a unicellular organism? An organism made of only one cell. For example: bacteria, amoebas.
What is a multicellular organism? An organism made of more than one cell.
Things that are NOT made of cells
Did you know??? Your body contains more than 75 trillion cells!!! 75,000,000,000,000
That’s enough cells to wrap around the Earth 47 times!!!