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Introduction to Cells. Smallest Units of Life. What are cells?. Cells are the smallest structural and functional units of life. Your Body Has 90 Trillions Cells. That's a 90 followed by 12 zeros. Form Follows Function. The shape of a cell depends on what the cell does.
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Introduction to Cells Smallest Units of Life
What are cells? • Cells are the smallest structural and functional units of life.
Your Body Has 90 Trillions Cells • That's a 90 followed by 12 zeros.
Form Follows Function • The shape of a cell depends on what the cell does. • Muscle cells are different than bone cells.
Plant Cells • Plant cells have flat sides and are green because of a chlorophyll (pigment).
Animal Cells • Animal Cells are generally pictured as round but they could be other irregular shapes.
What’s inside of cells? • Cells contain structures called “organelles” which means little organs.
Nucleus • The most important organelle because it contains DNA (genetic information).
Eukaryotic Cells • Eukaryotic Cells have a Nucleus. • Example-Plants and Animals
Prokaryotic Cells • Prokaryotic Cells like Bacteria do not have a Nucleus.
Cell Size • Cells can’t get too big or they will break like a water balloon.
Who discovered cells? • Robert Hooke discovered cells looking at cork under a microscope hundreds of years ago.
How are cells viewed? • Cells are generally viewed with a compound microscope that has 2 or more lenses.
Microscopes • Resolution-makes images clearer • Magnification-makes object bigger.
The modern microscope • Stage-where you put the slide. • Objectives-magnify image
Microscope lens • Microscope lenses are convex. • This means that they are curved outward like a fish eye.
Levels of Organization Cells form tissues which then form organs.
Scanning Electron Microscope • An SEM is one of the most powerful kinds of microscopes.
Single Celled Organisms • Some organisms like these bacteria are made of only one cell.
Cell Theory • All living things are made of cells. • Cells are the basic structural and functional units of life. • All cells come from other cells.
Thanks for your attention! • Study hard for the test!