Microbio Ch 1
The "Old Friends" hypothesis suggests that _____
Early exposure to certain microorganisms helps protect individuals from allergies, asthma, and some other diseases
How microorganisms are useful in the study of higher life forms
Microorganisms have the same basic metabolic mechanisms, multiply quickly, are cheaper to study, and have the same fundamental genetic properties.
What can viruses infect?
Plants, Animals, Protists, Bacteria, and Fungi
Consider the Human Microbiome Project begun in 2007. The term microbiome has which two overlapping meanings?
The microbial community itself, and the total genetic content of a microbial community
What is biotechnology?
The use of microorganisms to solve practical problems
How do fungi gain energy?
They degrade organic materials with enzymes
Why were Louis Pasteur's experiments with swan-necked flasks so important in helping disprove the theory of spontaneous generation?
They ended arguments that a "vital force" was necessary for spontaneous generation, while preventing contamination from microbes in the air.
Bacteria that are rod shaped are called
bacilli/bacillus
Plague is a _______
bacterial disease that can be transmitted by fleas
Most bacteria divide by a process called___in which one cell enlarges and then divides
binary fission
Peptidoglycan is found in the _____
cell walls of bacteria
In algae, photosynthesis takes place in ______, which have chlorophyll, a green pigment
chloroplasts
Technically speaking, viruses are not microorganisms because they are not ______
composed of cells
Cocci that divide in perpendicular planes form _____
cubical packets
The microscopic filaments of molds are called ______
hyphae
examples of emerging infections diseases
mad cow disease, Zika, Lyme disease, Ebola
The Golden Age of Microbiology is the period in which _____
many disease-causing microorganisms were discovered
The Germ Theory of Disease states that _____
microorganisms cause certain diseases
A mycelium is a(n) _____
network of hyphae produced by molds
The genetic material in prokaryotic cells is located in a region of the cytoplasm called the
nucleoid
Characteristics of viroids
It consists of RNA and can infect plants
_______ showed that flasks containing various broths gave rise to microorganisms even when the flasks were boiled and sealed with a cork.
John Needham
Which defines spontaneous generation?
Life arose from non-living matter
Bacteria that are sphere-shaped are called
cocci/coccus
Most bacteria have rigid cell walls that contain a unique compound called
peptidoglycan
The dividing bacterial cells can stick to each other. They can form characteristic arrangements such as pairs, chains, or clusters, depending on the _______
plane of division
Commercially valuable products from microorganisms include _______, which is used in the manufacture of disposable diapers and plastics
polyhydroxybutyrate
Spongiform encephalopathies are caused by infectious proteins. This information indicates that the infectious agent is a(n)
prion
Which are the most resistant to sterilization techniques?
prions
Lazzaro Spallanzani's experiments of 1776 showed that flasks of broths that had been boiled for long periods of time and sealed tight ______
remained free of microorganisms
Although archaea and bacteria differ in a number of important characteristics, it was ultimately significant differences in their _______ that provided the basis for separating the two groups of prokaryotes into different domains.
ribosomal RNA sequences
characteristics of protozoa?
single-celled eukaryotes, ingest organic materials as food sources
The species names of Escherichia coli and Escherichia vulneris reflect the _____
site where the organisms may be found
If Pasteur had performed his spontaneous generation experiments in a horse stable, his results would likely have ______
supported the idea of spontaneous generation
Slight genetic variations among members of the same species are indicated by assigning
strain designation
Escherichia coli K12 and Escherichia coli B belong to different _____
strains
What did the the Human Microbiome Project do?
used DNA sequencing to characterize microbial communities that inhabit the human body
Bioremediation refers to _____
using bacteria to clean up pollutants
You discover an agent that multiplies in plant cells and consists of only a single RNA molecule. It must be a(n) ______
viroid
Unlike the term microorganism, the word microbe also includes _____
viruses
The microbial world includes three main agents that cannot reproduce independently and are thus considered non-living. These are the...
viruses, viroids, and prions
Prions are misfolded proteins that cause ______
the normal version of the protein to also misfold
Microscopic fungi that are single-celled are called ______, and that that are multicellular and filamentous are termed _______
yeasts; molds
In 1749, John Needham produced results that _______ spontaneous generation when he showed that broths that had been boiled and then sealed with a cork _______.
support; could still give rise to microorganisms
The genus name Escherichia originates from _____
the name of the scientist
In research, a model organism should _____
Function in a manner similar to other organisms
Viruses are ______
obligate intracellular parasites
Algae and protozoa are also referred to as ___ a diverse group that falls within the domain Eukarya
protists
John Tyndall's experiments in the 1870s showed that microorganisms remained in some broths even after boiling for 5 hours. This was later explained by presence of endospores in his broths. Pasteur might have had results similar to Tyndall's if he had used which two materials to make his broths?
soil and hay
What is a helminth?
a worm, some of which are parasitic
Tyndall and Cohn's experiments in the 1870s showed the presence of a heat-resistant form of bacteria called an
endospore
In what ways are archaea similar to bacteria?
energy sources used, prokaryotic cell structure, method of multiplication, and shapes and sizes
Which are produced by microorganisms?
ethanol and antibiotics
characteristics of algae?
eukaryotic, photosynthetic, unicellular or multicellular
A bacterium that is pleomorphic is one that _____
exists in different shapes
The work of John Tyndall and Ferdinand Cohn ______
explained why some spontaneous generation investigators got different results from those of Pasteur
Who experimented with raw meat, worms, and flies in an attempt to disprove spontaneous generation?
francesco redi
Characteristics of viruses
Consist of nucleic acid and protein, acellular, and nonliving
Because less than 1% of microorganisms can currently be grown in the laboratory, most of what we know about the other 99% comes from _____
DNA sequencing
Prions are _______ that cause a number of diseases in ______
infectious proteins; animals
What killed more people in 1918-1919 than died in World Wars I and II and the Korean, Vietnam, and Iraq wars combined
influenza
Protozoa are _______ eukaryotes that _______ a rigid cell wall
unicellular; lack