Aristotle did __________.(bio)
Observed numerous animal species and realized that there was
"something" there, but he didn't have the technology to
further explore.
The Janssen Brothers
Made a crude Compound Microscope (two lenses) in 1590 -made distant
objects look closer by enlarging them.
Robert Hooke (bio)
Made his own compound microscope (two lenses) when observing a cork.
He discovered that the cork looked like cells, so he was the first one
to coin the term "cells
Pieces of a microscope
#NAME?
Antoni van Leeuwenhoek (Bio)
Made detailed drawings and observations of living organisms in a pond
of water -which he called animalcules- using a simple microscope (one
lens)- because of this he is considered the "father" of microbiology
magnification calculation
Ocular Lens x Objective Lens = magnification
Low Power Objective: 4x
Medium Power Objective: 10x
High Power Objective: 40x
Size of Object calculation
size of object: Diameter of Field of View (FOV) / number of times
object fits across FOV
Field of View Calculation
FOV (x) = FOV (y) x magnification (y) / magnification (x)
Spontaneous generation
The idea that life could simply spontaneously emerge from non-living matter.
-idea was disproved by Louis Pasteur
Francesco Redi
Believed that maggots arose spontaneously from rotting meat. He
disproved this when he had three jars:
1. No Lid = maggots
2. Lid = maggots
3. Cheese Cloth = maggots
John Needham
Used boiling to kill bacteria -did an experiment where he boiled
chicken broth and put it in an unsealed flask and soon it was cloudy
with bacteria, spontaneous generation was "proved
Lazzaro Spallazani
Expanded on Needham's findings -results of experiment
1- Boiled soup 1hr and glass sealed off = no bacteria
2- Boiled soup few mins and glass sealed off = bacteria
3- Boiled soup 1hr and glass sealed with cork = bacteria
Louis Pasteur
Disproved spontaneous generation by (furthering Needham's
experiments) taking fermentable juice and sterilizing it and put it in
a flask with a neck that was a thin, swan like, and no bacteria was in
the juice, not even when the neck was unsealed.
Matthias Schleiden
Believed that the plant ovary acted only as an incubator and the
pollen grain carried all the genetic material. He said that "all
plants are composed of cells
Theodor Schwann
Claimed that animal cells had a nucleus which was surrounded by a
watery substance and a thin membrane; as well, animals cells lacked
cell walls found in plants. He said that "the bodies of animals
and plants are composed of cells and the products of cells
Rudolf Virchow (bio)
Said that all cells only arise from pre-existing cells
The Cell Theory
1- All living things are made up of one or more cells and the
materials produced by these cells
2-All life functions take place in cells, making them the smallest
unit of life
3-All cells are produced from pre-existing cells through the process
of cell division
credit: Schleiden Schwann, Virchow
Contrast
The ability to see differences between structures due to differences
in their capacity to absorb light
Resolution
The ability to distinguish between two structures that are close together
Light Microscope
Uses one or more curved lenses and a light to magnify cells, but it
does not show details of the specimen. The light Microscope does not
have: contrast, or resolution
Brightfield Microscope
The illumination in the light microscope in which the specimen is
illuminated by an unfiltered beam of white light that passes from one
light source through the specimen, into the object, and the eye piece.