Lesson Plan - Get It!
It's BIG and GREEN, and it's MOVING! Should you be afraid of this living creature? Not unless you have a fear of pine trees blowing in the wind! Organisms come in many sizes, shapes, and colors. How else do creatures differ? How are they the same?
Here's a clue: Can you identify the objects in this picture?
Were you able to determine what is in the picture?
They're cells; plant cells, to be specific. The photo of the plant cells above was taken from a microscope at more than 500 times their size!
Every living organism is made up of cells, but before we get to the small picture, let's make our way down from the big picture to learn about how we know about cells today!
What is a species?
- Each different kind of organism on Earth is a species.
What is so special about species?
- Individuals in a species share certain characteristics.
- Example: All human beings belong to a species called homo sapiens.
- Only members in a species can mate and produce offspring.
All species have one thing in common:
- Their organisms are made of cells.
How were cells discovered?
- Scientist Robert Hooke used the compound microscope to look at a piece of a cork.
- He saw many little boxes separated by walls.
- He named these boxes cells.
- Today, we use the name cells to refer to microscopic building blocks of all living things.
What is the cell theory?
- Some organisms are made of only one cell while others are made of many cells.
- It took many more years for scientists to learn what cells were.
Scientists developed the cell theory.
- The cell is the basic unit of all living things.
- Only living cells can produce new living cells.
- All living things are made of cells.