Download Cell Theory Notes Spontaneous Generation – People believed that

Cell Theory Notes
Spontaneous Generation – People believed that under the right conditions living things could
spontaneously appear from non-living material
Redi’s Experiment – rotting meat in two containers, one covered in clothe
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Hypothesis – if a jar is covered than rotting meat will produce no flies
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Result – correct, flies lay eggs that develop into maggots and turn into flies
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Objection – sealing the jar prevented a magical essence from entering the rotting meat
History of the Microscope – 1650’s two versions built independently
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Leeuwenhoek – studied pond water and found “animalcules”
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Hooke – Studied Cork, named the structures cells
Spallanzani’s Experiment – boiled broth in two flasks, put a stopper on one, left the other open
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Hypothesis – If air is allowed to reach the food, then microbes will get in and spoil the food
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Result – unstopped flask with broth spoiled
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Objection – stopper prevented magical life force from entering
Luis Pasteur – Father of Microbiology
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Hypothesis – boiled broth kept free of bacteria, than it will not spoil even when exposed to
air – used a swan necked flask
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Result – No bacteria, dispelled Spontaneous Generation
Cell Theory Three Parts
1. All living things contain at least one cell
2. Cells are the smallest structural and functional units of life
3. Cells can only come from pre-existing cells
Matthias Schleiden – 1838, concluded that all plant parts are made of cells
Theodor Schwann – 1839, concluded that all animal tissue are composed of cells
What is Life?
1. Living things are composed of cells
2. Living things have different Levels of Organization
3. Living things use Energy
4. Living things Respond to their environment
5. Living things Grow
6. Living things Reproduce
7. Living things Adapt/Evolve to their environment over time
Rudolf Virchow – 1858, concluded that cells must arise from preexisting cells
Modern Cell Theory
1. The cell contains hereditary information (DNA) which is passed on from cell to cell
during cell division
2. All cells are basically the same in chemical composition (what they are made up of) and
metabolic activities (what they do)
3. All basic chemical and physiological functions are carried out inside the cells (movement,
digestion, respiration, protein synthesis, response to stimuli, etc.)
4. Cell activity depends on the activities of sub-cellular structures within the cell (organelles,
nucleus, plasma membrane)