Exam 1 Flashcards
List the steps of the scientific method.
- Observation and description of a phenomenon or a group of phenomena
- Formulate a hypothesis.
- Performance of properly designed experiments
- Draw conclusions.
List and describe the rules of science.
- Science is guided by natural law-physical and chemical laws govern the state of existence
- Science has to be explained by reference to natural law-no supernatural forces or causes or explanations allowed
- Science is testable against the empirical world-observations must be made in the real world for them to have scientific value
- Science’s conclusions are tentative-all scientific conclusions are subject to further verification
- Science is falsifiable-can be proven to be false
Define Theory
well substantiated explanation of some aspect of the natural world that can incorporate facts, laws, and tested hypotheseses
Define Law
descriptive generalization of how some aspect of the natural world behaves under stated circumstances
Define Fact
observation that has has been repeatedly confirmed and for all practical purposes is accepted as “true”
Define Hypothesis
tentative statement about the natural world leading to deductions that can be tested
How does general society vs. scientists use these terms?
Society ranks them Hypothesis, theory, law, then fact; while scientists rank them fact, hypothesis, law, then theory
Define microbiology
the study of living things too small to be seen with the naked eye (microorganisms)
Define taxonomy
The science of classification
Define Phylogeny
the study of evolutionary history of a group of organisms
Define prokaryotic species
a population of cells with similar characteristics
What are the main differences between a eukaryote and prokaryote?
Prokaryotes have no nucleus and no membrane-bound organelles.
Eukaryotes have a nucleus and membrane-bound organelles.
Why is the study of microbiology important?
To understand how the world around us works and the role of life on Earth; microbes are everywhere
How are all living things alike (structures and characteristics)?
Life is organized, requires energy, maintains equilibrium, reproduces, evolves, and has DNA
How did Aristotle and Linnaeus classify organisms?
Aristotle classified them in 2 groups, plants and animals, and Linnaeus classified them in two kingdoms that branched out
Explain Whittaker’s 5 Kingdom System of Classification. How does Woese’s Three Domain System of Classification relate to Whittaker’s system?
Whittaker divided into the 5 kingdoms of prokaryota/Monera, Protista, Fungi, Plantae, and Animalia
These relate because it shows how all living things can be grouped into smaller divisions more like one another
How were bacteria classified according to the 5 Kingdom System?
They were classified in the prokaryotae/monera kingdom
What was the basis for Woese to classify organisms in the Three Domain System?
Sequenced the 16S portion of the ribosomal RNA to show evolutionary relatedness
What is a ribosome?
Site of protein synthesis that is composed of RNA and proteins
Explain the endosymbiotic therory some lines of evidence which supports the Endosymbiotic Theory.
cells evolved a nuclear membrane; eukaryotic cell organelles evolved from prokaryotic cells living inside of the cell
Chloroplast and Mitochondrial Evidence-they have double membranes,only be produced by division of pre-existing mitochondria and chloroplasts, have their own naked and circular DNA, and the have ribosomes that are 70S in size
Why are ribosomes important in studying phylogeny?
They are in all cells and the sequence is fairly similar so that when it is different the change stands out
Explain/List the rules of scientific (binomial) nomenclature and its importance.
1.Genus is capitalized
2. Second name of species, the specific epithet is not capitalized
3.Always underlined or italicized
4.usually tells you something about the organism
The importance is that one organism has the exact same name regardless of where in the world the person is that is talking about it
Manual used to identify bacterial species.
Bergey’s Manuals (there is 2)
Robert Hooke
Used improved microscope and observed “cells” in cork tissue
Cell Theory
van Leeuwenhoek
Viewed “animalcules” in rainwater and materials he scraped from his teeth
What is spontaneous generation
Belief that life arises from dead tissue or non living matter
Francesco Redi (describe his experiments)
Tried to refute animalcules by taking 6 jars and filling them with decaying meat. Three of them were covered and the other three uncovered. There were maggots on the open jars and non on the closed. The problem people had with his experiment is that they said the animalcules needed air to generate
Spallanzani (describe his experiments)
Boiled nutrients solutions in flasks to kill animalcules. He placed the nutrient broth in a flask, sealed it, and then heated it. Again people said there needed to be air.
Louis Pasteur (describe his experiments)
Repeated Spallanzani’s experiment of boiling nutrient broth but did it instead in a swan neck flask so that air could enter in
What else did Pasteur’s experiment contribute to the study of microbiology?
Showed that microbes are present on non-living matter, microbes can be destroyed by heat, airborne contamination can be obstructed and air itself doesn’t create microbes, these discoveries are the basis for aseptic technique
Fracastoro
Germ Theory first proposed; Microorganisms are the causative agent for disease; people didn’t believe for centuries, believed that disease was due to demons or for punishment
Semmelweis
Hand washing prevented childbirth (childbed) fever; start of applying germ theory to medicine even though they didn’t realize it at the time; ran obstetrical clinics
Lister
Phenol on wounds to reduce infection; bacteria cause surgical wound infections; Listerine
Koch
First to show that bacteria actually caused diseases; created postulates
1. Same pathogen present in every case of disease
2. Pathogen isolated from disease host and growth in pure culture
3. Pathogen from pure culture must cause disease when inoculated into a healthy animal
4. Pathogen isolated from inoculated animal is shown to be the original organism