lesson 2 discovering the cell 2015
TRANSCRIPT
Lesson #2
How were cells discovered?
Prof. Beatriz Duro SEK Ciudalcampo International School
Discovering the principles of the microscope
In 1590, Zacharias Janssen, a Dutch eyeglass maker.
2 overlapped lenses increase magnification
Anton Van Leewenhoek (1632-1723)
Father of microbiology First to observe living
organisms smaller than what the human eye can see.
Robert Hooke Scientist Made an improved
microscope. First used the word
“cell” to indicate what living beings are made of.
What Hooke saw…
Cells
A pause In the following
years Hooke’s discovery didn’t have much influence in science.
S. XVII y XVIII Scientists were focused on classifying new species discovered by explorers.
In the early 19th Century they had a revolutionary idea in Germany.
Living things are made of living units
They started studying plants and animals at a microscopic level again.
Mathias Schleiden
Botanic
Proved that all fragments of plants
have the cells described by Hooke.
Theodor Schwann
zoologist
Proved that all fragments of
animals also have cells.
Both came up with a theory that said that all organisms come from a cell and develop from there by the formation of new cells. CELL THEORY.
18381839
The Cell TheoryLate 19th C.
All living things are formed by one or more cells
A cell is the smallest and simplest living thing.
All cells come from other pre-existing cells. All cells can function independently,
although they work together in a coordnated way when part of an organism. One cell can perform all living functions : nutrition,
reproduction and interrelation
20th Century interest: The cell 1930 invention of
the Electron Microscope: uses electrons
instead of light. Resolution 0.5
nm. Allows to see cells
in detail.
Electron Microscope Images
What do you think this is? And this?
VIDEO
HOMEWORK
Draw, label and describe organelle functions.
HOMEWORK