1.Cells of life
Grade 8 Science/2011 Term 3
Chapter 4
Compiled by Madre Nortje

2. Cells of life chapter 4Grade 8
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Compiled by Madre Nortje
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4. What will you know ?
collect information about the microscopic structure of organisms
identify the similarities and differences between plant and animal cells
explain the cell theory and link its development to that of microscopes
draw diagrams of cells and tissues seen under the microscope
explain cell specialisation and give some examples found in plants
and animals
make connections between organisation at the cellular, tissue, organand system levels
relate structure and function at different organisational levels.
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5. Cell theory
There is no typical cell shape.
Cells come in shapes such as cubes (cells lining sweat ducts), spheres (white blood cells in the immune system), columns (cells lining the stomach), rods (some bacteria) and pancakes (cells on the surface of the skin).
All living things are made up of cells.
Cells are the basic units of structure and function in living things.
All cells arise from pre-existing cells.
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6. CELL THEORY
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FIRST TWO PRINCIPLES
Matthias Schleiden and Theodor Schwann
All living things are made up of cells
Cells are the basic units of structure and function in living things.
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7. Third principle
Further work by Rudolf Virchow led to
3.All cells arise from pre-existing cells.
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8. History: important dates in the study of cells
Year Event
1590 Hans and Zacharias Janssen invented the first microscope.
1665 Robert Hooke saw cells in cork. He first used the name cells.
1675 Anton van Leeuwenhoek saw bacteria in tooth plaque.
1838 Matthias Schleiden stated that all plants are made of cells.
1839 Theodor Schwann and Matthias Schleiden proposed the cell theory.
1858 Rudolf Virchow found that cells are able to reproduce.
1860 Ernst Abbe invented the first modern microscope.
1865 Louis Pasteur found that bacteria cause disease.
1931 Max Knoll and Ernst Ruska made the first electron microscope.
1942 Viruses were fi t seen under an electron microscope.
1973 The first successful genetic engineering experiment was performed.
1978 The first baby was born through in-vitro fertilisation (IVF).
1980 to present Further advances were made in genetic engineering and IVF.
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9. Robert hooke1665 microscope
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Used Light from a candle directed by a lens onto the specimen
10. THE MICROSCOPE
Van Leeuwenhoeks microscope
One lens mounted in a tiny hole brass plate.
Adjusted the position and the focus by turning two screws.
First person to observe organisms in water
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11. anton van leeuwehoek
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12. Anton van Leeuwenhoek
A Dutch drapper
Used lenses to examine pieces of cloth he want to buy
Began to use lenses to look at other things
Made about 500 microscopes few still survive today
Called microscope but only Powerful magnifying glasses
Could magnify 270 times
Could see smaller thing than Hooke could
1675 Observe living things in stagnant water
1683 Observed bacteria under his bacteria A FIRST
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15. Water organisms
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HOW DOES A CELL LOOK LIKE ?
3 D (Three Dimensional Model of a cell) - picture
Parts of a cell is called ORGANELLES
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CELL ORGANELLES
3 D (Three Dimensional Model of a cell) - picture

There are many different types of cells.

18. Cell is made up of many parts. 19. Not all cells contain all of these parts; it depends on what particular job the cell does. 20. These parts are called organelles.