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Cell Theory-1
The document summarizes the Cell Theory, which states that: 1) All living things are made of one or more cells. 2) The cell is the basic unit of life. 3) New cells are produced from existing cells. The modern Cell Theory contains four additional statements about cells containing DNA, having similar chemical composition and metabolism, carrying out basic functions, and depending on organelle activities. The document also discusses why cells are microscopic due to limitations in surface area to volume ratio for nutrient exchange if cells were larger.
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Cell Theory-1
- 1. The Cell Theory HLBiology Cells & Biomolecules
- 2. Cell theory 1. Discusswith your neighbors what “cells” are. 2. Compile your ideas in a mind map on the whiteboard
- 3. History of celltheory
- 4. The Cell Theory Complete The3 Basic Components of the Cell Theory were now complete: 1.All organisms are composed of one or more cells. 2. The cell is the basic unit of life in all living things. 3. All cells are produced by the division of preexisting cells.
- 5. Modern Cell Theory ModernCell Theory contains 4 statements, in addition to the original Cell Theory: •The cell contains hereditary information(DNA) which is passed on from cell to cell during cell division. •All cells are basically the same in chemical composition and metabolic activities. •All basic chemical & physiological functions are carried out inside the cells.(movement, digestion,etc) •Cell activity depends on the activities of sub-cellular structures within the cell(organelles, nucleus, plasma membrane)
- 6. Cell theory facts 5minute activity: Use the internet to find 3 interesting or bizarre facts about cells PS, we already know that the human body is made up of roughly 100 trillion cells, so find a different fact!
- 7. Why are cells microscopic? Discussthe following question with the people at your table: “Why are cells so small?”
- 8. Exploring surface area andvolume Head to the following link: http://bit.ly/1n0AROF Explore the relationship between surface area and volume. What do you notice happens to surface area as the volume is increased?
- 9. Implications of Cell Theory Thesame principle applies to cells. If the volume increases the surface area will also increase, but at a lower rate. What happens to the surface area/volume ratio as the size of a cell increases?
- 10. The Limits ofCell Size The cell surface (cell membrane) is the site of particle exchange between the inside of the cell and the external environment The cell surface must allow for sufficient movement of particles and nutrients into the cell and waste products out of the cell.
- 11. The Limits ofCell Size Surface-area to volume ratio too small = decreased rate of chemical exchange cell dies Therefore… in order to build larger organisms, they must be built up from small cell subunits.