Section 1 Bio Flashcards
what did Han and Zacharias Janssen do?
They invented the microscope in 1595.
-2 lens
-magnifying power of 20X
-compound microscope
what did Robert Hooke do?
Improved the Janssens’ design.
-added third lense
-added a light to illuminate the objects
what did Antoni Van Leeuwenhoek do?
Created the single lens microscope.
-lense was higher quality (250X)
-was the first person to observe the movement of living single-celled organisms
what is the revolving nose piece?
rotates mount that holds many objective lenses.
what is the coarse adjustment knob?
moves the stage of the microscope up and down to bring the specimen into the focal plate of the objective lens.
what is the objective lens?
gathers light from a specimen and forms an inverted image.
what is low power, medium power, and high power?
low power: 4X
Med power: 10X
High power: 40X
what is field of view?
the area that can be seen through the microscope with a particular objective lens.
what is Scale?
a comparison between the size of a drawing and the actual size of the object.
what is Spontaneous Generation?
the belief that living things can emerge from non-living matter.
who did Francisco Redi do?
set up an experiment to illustrate that maggots did not grow spontaneously from raw meat.
-one flask with access to air
-one flask without access to air
The flask was open to air and had evidence of maggots.
Other scientists said that air is a necessary ingredient in life force.
what did John Needham do?
Performed the chicken broth experiment.
-boiled chicken broth (to kill bacteria)
-sealed it in a flask
-found that microorganisms still appeared.
likely because didn’t boil it long enough
what did Lazzaro Spallanzani do?
Repeated Needham’s experiment but in a vacuum.
-this removed all the air in the flask.
-no microorganisms appeared
-still proved that air is an ingredient in life force.
what did Louis Pasteur do?
his experiment in 1864 proved the scientific community needed to reject spontaneous generation once and for all.
-he set up 2 flasks with long necks so they were open to air but protected from dust (meat broth in both)
-neither broth became cloudy with microbial growth
-after, he broke the neck off of one flask
- overtime microorganisms appeared in the broken flask but not the other flask that was still intact.
what did Pasteurs experiment prove?
microorganisms appeared in the broken flask and not the other flask. it showed that microorganisms don’t just spawn…they are carried through the air.
what did Robert Brown do?
identified the nucleus of the cell as being responsible for controlling cell function.
what did Schleiden and Schwann do?
proposed that all plants and animals are composed of cells.
-described cells as the basic unit of life for all organisms.
What is the entire summary of cell theory?
-all living things are made up of cells and the materials produced by these cells.
-all life functions take place in cells, making then the smallest unit of life.
-all cells are produced from pre-exsisting cells through a process of cell division.
what is contrast?
the variation of shadow and colour.
what is resolution?
the ability to distinguish between 2 structures that are very close together.
what is confocal technology?
provides a means of rejecting the out-of-focus light from the detector such that it does not contribute blur to the images being collected
what is electron microscopy?
uses a fine beam of electrons instead of light.
