Objective: SWBAT explain the main ideas of cell theory
Objective: SWBAT explain the main ideas of cell theory
Read the following passage. Then MARK UP THE TEXT by highlighting,
underlining, circling, writing notes on the left or right hand side of
the paper, etc. on the important concepts and ideas.
CELL THEORY
Read the following passage. Then MARK UP THE TEXT by highlighting,
underlining, circling, writing notes on the left or right hand side of
the paper, etc. on the important concepts and ideas.
CELL THEORY
Human understanding of nature often follows the invention and
Human understanding of nature often follows the invention and
improvement of instruments that extend human senses. The development of
improvement of instruments that extend human senses. The development of
microscopes provided increasingly clear windows to the world of cells. Light
microscopes provided increasingly clear windows to the world of cells. Light
microscopes, the kind used in your classroom, were first developed and used
microscopes, the kind used in your classroom, were first developed and used
by scientists around 1600. In a light microscope, visible light passes through
by scientists around 1600. In a light microscope, visible light passes through
the object such as a thin slice of muscle tissue, and glass lenses then enlarge
the object such as a thin slice of muscle tissue, and glass lenses then enlarge
the image and project it into the human eye or a camera.
the image and project it into the human eye or a camera.
In 1665, an English scientist named Robert Hook observed
In 1665, an English scientist named Robert Hook observed
compartments in a thin slice of cork (oak bark) using a light microscope. He
compartments in a thin slice of cork (oak bark) using a light microscope. He
named the compartments cells. Actually, Hooke was observing the walls of
named the compartments cells. Actually, Hooke was observing the walls of
dead plant cells. Many more observations by many other scientists were
dead plant cells. Many more observations by many other scientists were
needed to understand the importance of Hooke’s discovery. By 1700, Dutch
needed to understand the importance of Hooke’s discovery. By 1700, Dutch
scientist Anton van Leeuwenhoek had developed simple light microscopes
scientist Anton van Leeuwenhoek had developed simple light microscopes
with high-quality lenses observe tiny living organisms, such as those in pond
with high-quality lenses observe tiny living organisms, such as those in pond
water. He described what he called “animalcules” in letters to Hook and his
water. He described what he called “animalcules” in letters to Hook and his
colleagues.
colleagues.
For the next two centuries, scientists using microscopes, found
For the next two centuries, scientists using microscopes, found
cells in every organism they examined. By the mid-1800’s, this evidence led
cells in every organism they examined. By the mid-1800’s, this evidence led
to the cell theory. The cell theory states that all living things are composed of
to the cell theory. The cell theory states that all living things are composed of
cells and those cells are the basic unit of structure and functions in living
cells and those cells are the basic unit of structure and functions in living
things. Later, the cell theory was extended to include the concept that all
things. Later, the cell theory was extended to include the concept that all
cells come from preexisting cells.
cells come from preexisting cells.
Summarize what you have read with 2 sentences!
Summarize what you have read with 2 sentences!
Questions
Questions
1.
2.
3.
Who was Robert Hooke? What did he discover?
1.
Who was Robert Hooke? What did he discover?
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Who was Anton van Leeuwenhoek? What did he discover?
2.
Who was Anton van Leeuwenhoek? What did he discover?
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What are the three key ideas of the cell theory?
3.
What are the three key ideas of the cell theory?
1. ________________________________________________
1. ________________________________________________
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2. __________________________________________________
2. __________________________________________________
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4. __________________________________________________
3. __________________________________________________
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