What is microbiology?
study of life too small to be seen by unaided eye (microbial world)
How did people figure out that there were microbes?
Development of the microscope.
The highest level in biological classification. There are 3 domains: Bacteria, Archaea, & Eukarya.
Organism composed of 1 or more eukaryotic cells; members of the domain Eukarya & eukaryotes.
Define Eukaryotic Cell
Cell type characterized by a membrane-bound nucleus
An acellular infectious agent consisting only of protein.
single-celled organism consisting of a prokaryotic cell; members of the domains Bacteria & Archaea are prokaryotes.
Define prokaryotic cell
Cell type characterized by the lack of membrane-bound nucleus.
An acellular infectious agent consisting only of RNA
An acellular infectious agent consisting of nucleic acid surrounded by a protein coat.
Define Spontaneous Generation
Life arose from non-living matter
In 1749, John Needham produced results that ____ spontaneous generation when he showed that broths that had been boiled & then sealed with a cork ____.
support; could still give rise to microorganisms.
Lazzaro Spallanzani's experiment of 1776 showed that flasks of broths that had been boiled for long periods of time & sealed tight ____.
remained free of microorganisms.
Francesco Redi first disproved the theory of spontaneous generation by showing that ___.
worms only appear on decaying meat has been exposed to flies.
Tyndall & Cohn's experiments in the 1870s showed of a heat-resistant form of bacteria called a(n)
The Golden Age of Microbiology is the period in which...
many disease-causing microorganisms were discovered.
The principle that microorganisms cause certain diseases is called the ___ Theory.
The property of endospores that led to confusion in the experiments on spontaneous generation is their ___.
If all prokaryotes were eliminated from the planet,
all animals would die
All of the following are emerging infectious disease except...
All of the following are biological domains except...
Which name is written correctly?
Members of which pairing are most similar in appearance to each other?
Archaea & Bacteria
contain both protein and nucleic acid
Antonie van Leeuwenhoek could not have observed...
The Scientific Method
Scientific Method includes (1) observing occurrence & asking a question about that situation; (2) developing a hypothesis that explains the occurrence & devising an experiment that tests the hypothesis; (3) doing the experiment, collecting the data, & drawing conclusions; & (4) communicating the results, methods, & conclusions.
What is a scientific theory?
An explanation supported by a vast body of experimental evidence.
The production of living things, as opposed to spontaneous generation.
The experiments of John Needham supported the idea of spontaneous generation, while those of Lazzaro Spallanzani did not.
Experiments of Pasteur
Pasteur disproved spontaneous generation & supported what is now known as the theory of biogenesis.
Experiments of Tyndall
John Tyndall showed that some microbial forms are not killed by boiling. He & Ferdinand Cohn discovered endospores, the heat-resistant forms of some bacteria.
Commercial Benefits of Microorganisms
Microorganisms are used in the production of bread, wine, beer, & cheeses. They are also used to degrade toxic pollutants and to synthesize a variety of different useful products. Biotechnology depends on members of the microbial world.
The use of microbiological & biochemical techniques to solve practical problems & produce valuable products.
Microbes as Research Tools
Microorganisms are wonderful model organisms to study because they have the same fundamental metabolic & genetic properties as higher life-forms, & they grow rapidly on simple, inexpensive growth media.
Bacteria are single-celled prokaryotes that have peptidoglycan in their cell walls.
sphere-shaped bacterial cell.
Cylinder-shaped bacterium; also called a bacillus
short, curved, rod-shaped bacterial cell
curved rod-shaped bacterial cell that is long enough to form spirals
Long, helical bacteria that have flexible cell wall & endoflagella
single-celled yeasts & multicellular molds & mushrooms; they use organic compounds as food
single-celled or multicellular, & use sunlight as an energy source
typically motile single-celled organisms that use organic compounds as food.