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7-1 Life Is Cellular
Photo Credit: © Quest/Science Photo Library/Photo Researchers, Inc.
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2. The Discovery of the Cell
Early Microscopes
In 1665, Robert Hooke used a microscope to look at a thin slice of cork.
Cork looked like thousands of tiny, empty chambers he called “cells”.
Cells are the basic units of life.
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3. The Discovery of the Cell
Hooke’s Drawing of Cork Cells
hoto Credit: © Peter Arnold, Inc.
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4. The Discovery of the Cell
At the same time, Anton van Leeuwenhoek used a single-lens microscope to observe pond water.
The microscope revealed a world of tiny living “animacules”.
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5. The Discovery of the Cell
The Cell Theory
In 1838, Matthias Schleiden concluded that all plants were made of cells.
In 1839, Theodor Schwann stated that all animals were made of cells.
In 1855, Rudolph Virchow concluded that new cells were created only from existing cells.
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6. The Discovery of the Cell
The cell theory states:
All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.
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7. Prokaryotes and Eukaryotes
Prokaryotic cells have genetic material, but not in a nucleus.
No organelles.
Smaller and simpler.
Ex) Bacteria are prokaryotes.
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8. Prokaryotes and Eukaryotes
Eukaryotic cells contain a nucleus with the genetic material.
Have organelles.
Larger & more complex.
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9. Classification of Life
5 Kingdom System
Monera – prokaryotes
Plants – eukaryote, cell wall, chlorophyll
Fungi – eukaryote, cell wall, no chlorophyll
Animal – eukaryote, no wall, multicellular
Protista – eukaryote, no wall, unicellular
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7-1
The cell theory states that new cells are produced from
nonliving material.
existing cells.
cytoplasm.
animals.
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7-1
The person who first used the term cell was
Matthias Schleiden.
Lynn Margulis.
Anton van Leeuwenhoek.
Robert Hooke.
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7-1
Electron microscopes are capable of revealing more details than light microscopes because
electron microscopes can be used with live organisms.
light microscopes cannot be used to examine thin tissues.
the wavelengths of electrons are longer than those of light.
the wavelengths of electrons are shorter than those of light.
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7-1
Which organism listed is a prokaryote?
protist
bacterium
fungus
plant
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7-1
One way prokaryotes differ from eukaryotes is that they
contain DNA, which carries biological information.
have a surrounding barrier called a cell membrane.
do not have a membrane separating DNA from the rest of the cell.
are usually larger and more complex.
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