Click here to view Cell Structure and Function
Click here to view Cell Theory
Click here to view Plant and Animal Cells
Click here to view Cell Theory
Click here to view Plant and Animal Cells
Cells and Life
ESSENTIAL QUESTIONS
• How did scientists’ understanding of cells develop?
• What basic substances make up a cell?
Links
Cells-Lesson 1 Cells Alive Interactive Games cell theory rap Cell Theory Animation
The wacky history of cell theory Cell Theory Timeline BrainPop Cells Short Video Hooke
Cells and Life, Macromolecules, Cell Organelles Cell Reproduction
ESSENTIAL QUESTIONS
• How did scientists’ understanding of cells develop?
• What basic substances make up a cell?
Links
Cells-Lesson 1 Cells Alive Interactive Games cell theory rap Cell Theory Animation
The wacky history of cell theory Cell Theory Timeline BrainPop Cells Short Video Hooke
Cells and Life, Macromolecules, Cell Organelles Cell Reproduction
Understanding Cells
Have you ever looked up at the night sky and tried to find other planets in our solar system? It is hard to see them without using a telescope. This is because the other planets are millions of kilometers away. Just like we can use telescopes to see other planets, we can use
microscopes to see the basic units of all living things--cells. But people didn’t always know about cells.
Because cells are so small, early scientists had no tools to study them.
It took hundreds of years for scientists to learn about cells.
More than 300 years ago, an English scientist named Robert Hooke
built a microscope. He used the microscope to look at cork,
which is part of a cork oak tree’s bark. What he saw looked like
the openings in a honeycomb, as shown.
The openings reminded him of the small rooms, called cells,
where monks lived.
He called the structures cells, from the Latin word cellula (SEL yuh luh),
which means “small rooms.”
The Cell Theory
After Hooke’s discovery, other scientists began making better microscopes and looking for cells in many other places, such as pond water and blood.
The newer microscopes enabled scientists to see different structures
inside cells.
Matthias Schleiden (SHLI dun), a German scientist, used one of the
new microscopes to look at plant cells.
Around the same time, another German scientist, Theodor Schwann, used a microscope to study animal cells.
Schleiden and Schwann realized that plant and animal cells have similar features and carry on similarfunctions, such as extracting energy from food and eliminating wastes.
From this evidence, Schleiden and Schwann concluded that cells are the basic unit of life.
Almost two decades later, Rudolf Virchow (VUR koh), a German doctor, proposed that all cells come from preexisting cells,
or cells that already exist.The observations made by Schleiden, Schwann, and Virchow were combined into one theory.
Have you ever looked up at the night sky and tried to find other planets in our solar system? It is hard to see them without using a telescope. This is because the other planets are millions of kilometers away. Just like we can use telescopes to see other planets, we can use
microscopes to see the basic units of all living things--cells. But people didn’t always know about cells.
Because cells are so small, early scientists had no tools to study them.
It took hundreds of years for scientists to learn about cells.
More than 300 years ago, an English scientist named Robert Hooke
built a microscope. He used the microscope to look at cork,
which is part of a cork oak tree’s bark. What he saw looked like
the openings in a honeycomb, as shown.
The openings reminded him of the small rooms, called cells,
where monks lived.
He called the structures cells, from the Latin word cellula (SEL yuh luh),
which means “small rooms.”
The Cell Theory
After Hooke’s discovery, other scientists began making better microscopes and looking for cells in many other places, such as pond water and blood.
The newer microscopes enabled scientists to see different structures
inside cells.
Matthias Schleiden (SHLI dun), a German scientist, used one of the
new microscopes to look at plant cells.
Around the same time, another German scientist, Theodor Schwann, used a microscope to study animal cells.
Schleiden and Schwann realized that plant and animal cells have similar features and carry on similarfunctions, such as extracting energy from food and eliminating wastes.
From this evidence, Schleiden and Schwann concluded that cells are the basic unit of life.
Almost two decades later, Rudolf Virchow (VUR koh), a German doctor, proposed that all cells come from preexisting cells,
or cells that already exist.The observations made by Schleiden, Schwann, and Virchow were combined into one theory.