Chapter 1 Flashcards
Define pathogens
a microbe that damages a host via infection and disease
A vast majority of microbes are ________ and many are essential to human life
harmless
Define microbiology
the specialized study of biology that studies organisms too small to the naked eye (unicelled)
Define microbes
microscopic unicellular organisms too small to see with the naked eye
What is considered macroscopic
200 um to 2 mm
What is considered microscopic
1 um to 50 um
what is considered ultramicroscopic
0.5 nm to 200nm
what is considered atomic
0.1 nm
most ________ fall between 200 and 10 nm in size; what is required to view them
viruses; need electron microscope
Most _________ cells fall between 10 um and 1 um in size
bacterial
What do all prokaryotic cells have
ribosomes, cell membrane (or body), chromosomes
What do some prokaryotic cells have
flagellum and many have cell walls
What do all viruses have
capsid, nucleic acids,
What do some viruses have
bacteriophage, envelope
What do all eukaryotic cells have
ribosomes, cell membranes, mitochondria, and nucleus
What do some eukaryotic cells have
flagellum
What type of cell is prokaryotes
single celled
What type of cell is eukaryotes
not always single celled but has organelles and nucleus
Why are viruses considered not alive
can’t reproduce on its own–they need to parasitize another living cell
How long ago were prokaryotic cells appearing
3.5 billion
How long ago were eukaryotic cells appearing
1.8 billion
From the oldest to youngest when did the following appear by rank
termites
reptiles
humans
mammals
reptiles
termites
mammals
humans
how many years ago were humans on earth
millions
How did we know when bacteria like cells existed
fossil radiodating
Define spontaneous generation
antiqued believe that life arises from non-living matter
Why did we believe in spontaneous generation
lacked the technology to study microbes
What is Anton van Leeuwenhoek attributed to
development of the first microscope and microbial world (calculated their sizes)
In 1674 what did anton van leeuwenhoek discover
protozoa for the first time and several years later bacteria
Van leeuwenhoek’s research led to the acceptance of biogenesis and provided us with
examples of the early development of science-based thought
Define hypothesis
early explanation that deduces facts to what can account for what has been observed
Define deductive reasoning
general explanation of some phenomenon to develop a set of facts to explain that phenomenon
Define inductive reasoning
one applies specific observations to develop a general explanation
Define theory
collection of statements, propositions, or concepts that explain or account for a natural event
Define law
evidence of the accuracy is so compelling that the next level of confidence is reached and the theory becomes a law
When are observations used
in inductive reasoning
When are experiments used
when the hypothesis is valid and can allow for it
Who disproved spontaneous generation
louis pasteur
What is the theory of biogenesis and who found it
idea that living things can only arise from other living things; louis pasteur
What was the result of louis pasteur’s swan flask experiment
microbes were the cause of fermentation and making of food products but also the cause of infection
What is pasteurization
sterilization of food and medical devices
Who developed the first vaccine from actual microbes
pastuer
Who solidified the germ theory
koch
What did koch do
further advanced the ideas of pasteur by using the scientific method and working with some bacteria
What were the steps of koch
isolate organism from blood of infected animal, inoculate the bacteria into healthy animal, observe that these animals now showed similar symptoms, and re isolate the same microbe
What was the key finding of koch
bacteria are the causative agents of some diseases
State the 4 koch postulates
- microbes must be found in an abundance in all organisms suffering from the disease
- they must be isolated from a diseased organism and grown in pure culture
- they should cause disease when introduced into a healthy organism
- they must be reisolated from the inoculated experimental host and identified as being identical to the original specific causative agent
How is binomial nomenclature understood
genus –> species
Define classification
orderly arrangement of organism’s into groups that indicate evolutionary relation
What is the acronym for the nomenclature
king phillip came over for good spaghetti
What does phylogeny tell us
the natural relatedness between groups of living things
What was charles darwins main idea
all species of life have descended from a CA; natural selection
Define natural selection
individuals of a species are more likely to survive in their environment and pass on their genes to the next generation when they inherit traits from their parents that are best suited for that specific environment
What is the theory of evolution
living things gradually change over time as new generations of the organism come about
Theory of evolution process is _________
selective
Define phylogenetics
study of the evolutionary history and relationships among groups of organisms
What do nodes tell you
the next ancestor
two species are more related if they have more recent
CA
The most current system is based on the genetic structure of __________
ribosomes in the organism
What are the three domains in woese-fox system
bacteria, archaea, and eukarya
closely related organisms have similar what? and why?
features because they have evolved from common ancestral forms
Why are viruses not included in the most recent phylogenetic trees
they’re not cells and have no ribosomes
