History of the Cell The Cell Theory 1600s- 1665- 1700’s- 1838- 1839- 1855-

1600s- The light microscope is developed by Zaccharias Jansseen and his son, Hans Jansseen

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Hans Jansseen 1665- 1700’s- 1838- 1839- 1855-

1665- Robert Hooke observes the first cells. He coined the word ‘cell

Why do you think he called them cells?

Monk Cell Remains in Sanchi, Madhya Pradesh, India

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Han Jansseen 1665- Robert Hooke observes the first cells. He came up with the word “cell” & said all living things are made of cells 1700’s- 1838- 1839- 1855-

1700’s-Anton van Leeuwenhoek made a light microscope with higher quality lenses to observe smaller organisms (animalcules) First to see organisms living in a drop of water

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Han Jansseen 1665- Robert Hooke observes the first cells. He came up with the word “cell” & said all living things are made of cells 1700’s- Anton van Leeuwenhoek made a light microscope with higher quality lenses to observe smaller organisms (animalcules) living in a drop of water 1838- 1839- 1855-

1838, German botanist, Matthias Schleiden Concludes: All plants are made of cells.

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Han Jansseen 1665- Robert Hooke observes the first cells. He came up with the word “cell” & said all living things are made of cells 1700’s- Anton van Leeuwenhoek made a light microscope with higher quality lenses to observe smaller organisms (animalcules) living in a drop of water 1838- German botanist, Matthias Schleiden He concludes: All plants are made of cells. 1839- 1855-

. 1839, German scientists, Theodor Schwann Concludes: All animals are made of cells.

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Han Jansseen 1665- Robert Hooke observes the first cells. He came up with the word “cell” & said all living things are made of cells 1700’s- Anton van Leeuwenhoek made a light microscope with higher quality lenses to observe smaller organisms (animalcules) living in a drop of water 1838- German botanist, Matthias Schleiden He concludes: All plants are made of cells. 1839- German scientists, Theodor Schwann He concludes: All animals are made of cells. 1855-

1855, German physician, Rudolf Virchow studies: cell reproduction concludes after years of research: Where a cell exists, there must have been a preexisting cell…” “Omnis cellula e cellula”

History of the Cell The Cell Theory 1600s- The light microscope is developed by Zaccharias Jansseen and his son, Han Jansseen All living things are composed of cells Cells are the basic unit of structure and function in living things All cells come from pre-existing cells 1665- Robert Hooke observes the first cells. He came up with the word “cell” & said all living things are made of cells 1700’s- Anton van Leeuwenhoek made a light microscope with higher quality lenses to observe smaller organisms (animalcules) living in a drop of water 1838- German botanist, Matthias Schleiden Concludes: All plants are made of cells. 1839- German scientists, Theodor Schwann He concludes: All animals are made of cells. 1855- German physician, Rudolf Virchow studies: cell reproduction concludes after years of research: Where a cell exists, there must have been a preexisting cell…”

Create detailed images of something that is otherwise too small to see Light microscopes Simple or compound Electron microscopes Transmission EM electrons transmitted through specimen Scanning EM electrons beamed onto surface of the specimen Better Resolution minimum distance two points can be apart and still be distinguished as two separate points Microscopes

Comparison between microscopes Light microscope TEM SEM Source Light Electrons Specimen Living/ nonliving Nonliving Max. Resolution 200 nm 1 nm 10 nm Max. Magnification 1,500 x 200,000 x 100,000 x Stains Colored dye Heavy metal Type of image Colored Black/white

Limitations of Light Microscopy Wavelengths of light are 400-750 nm If a structure is less than one-half of a wavelength long, it will not be visible Light microscopes can resolve objects down to about 200 nm in size ocular lens objective lens stage condenser illuminator prism source of illumination

accelerated electron flow (top to bottom) Electron Microscopy viewing screen projector lens intermediate lens objective lens specimen condenser lens accelerated electron flow (top to bottom) Uses streams of accelerated electrons rather than light Electrons are focused by magnets rather than glass lenses Can resolve structures down to 0.5 nm

Visualizing Cells

Comparison between microscopes Light microscope TEM SEM Source Specimen Max. Resolution Max. Magnification Stains Type of image

History of the ________ The Cell Theory ________- The ________ microscope is developed by Zaccharias Jansseen and his son, Han Jansseen ___________________________________________________________ ______- Robert ________ observes the first cells. He came up with the word “______” & said all living things are made of cells _________- Anton van _____________________ made a _______ microscope with higher quality _________ to observe smaller organisms (animalcules) living in a drop of ____________ _________- German botanist, Matthias ____________ Concludes: All __________ are made of cells. _________- German scientists, Theodor _______________ He concludes: All __________ are made of cells. _______- German physician, Rudolf ___________ studies: cell __________________ concludes after years of research: Where a cell exists, there must have been a preexisting cell…”

Comparison between microscopes Light microscope TEM SEM Source __________ _________ Specimen __________/__________ Max. Resolution 200 nm 1 nm 10 nm Max. Magnification 1,500 x 200,000 x 100,000 x Stains Colored dye Heavy metal Type of image _________/_________