The Cell. Definition of Cell note: only write down text in red A cell is the smallest unit that is...
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Transcript of The Cell. Definition of Cell note: only write down text in red A cell is the smallest unit that is...
The Cell
Definition of Cellnote: only write down text in red
A cell is the smallest unit that is capable of performing life
functions.
Cell Theory
• All living things are made of cells. • Cells are the smallest living units. • All cells come from preexisting cells
through cell division.
Who came up with this theory?
1. Robert Hooke(1665)First person to see cells, he was looking
At cork and noted that he saw many boxes
That look like prison cells
Let’s call these things
cells!
Who came up with this theory?
2. Schleiden (1838)All plants are made of cells!
Onion skin cells
3. Schwann - 1839
Who came up with this theory?All animals are made of cells!
Human red blood cells
Who came up with this theory?
4. Virchow - 1855
All cells come from
pre-existing cells!
Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria
How big are cells?
• Mostly Microscopic
• Measured in microns (µm)
• A µm is one millionth of a meter!
How big are cells?
• Bacteria (aka E.coli)• Size=1 µm by 3 µm
How big are cells?
• Human red blood cell = 8 µm
How big are cells?
• Largest cell on the human body is the ovum
• 1000 µm in diameter
(1 mm)
Two Types of Cells
•Prokaryotic•Eukaryotic
Prokaryotic
• Do not have organelles surrounded by membranes
• Few internal structures
• Example: Bacteria
Eukaryotic• Contain organelles surrounded by membranes• Most living organisms are eukaryotes
Plant Animal
“Typical” Animal Cell
“Typical” Plant Cell