Chapter 4
Which of the following descriptions of biofilms are true? -Biofilms are able to enhance many bioremediation efforts -Biofilms are important in wastewater treatment facilities -Biofilms are involved in a small percentage of bacterial infections -Biofilms are involved in dental plaque, which can lead to tooth decay and gum disease -Bacteria in biofilms can be hundreds of times more resistant to disinfectants than their free-living counterparts
-Biofilms are able to enhance many bioremediation efforts -Biofilms are important in wastewater treatment facilities -Biofilms are involved in dental plaque, which can lead to tooth decay and gum disease -Bacteria in biofilms can be hundreds of times more resistant to disinfectants than their free-living counterparts
Which of the following is a chemically defined medium? -Glucose salts -Nutrient broth -MacConkey agar -Nutrient agar -Blood agar
-Glucose salts
Where are you likely to find biofilms? -In pipes, drains and water towers -In toilet bowls and sink drains -On the wall of your bedroom -On a restaurant kitchen countertop -In dental plaque on teeth -In the majority of bacterial infections -On rocks in a stream bed
-In pipes, drains and water towers -In toilet bowls and sink drains -In dental plaque on teeth -In the majority of bacterial infections -On rocks in a stream bed
Which of the following are characteristics of complex media that are enriched to support the growth of fastidious organisms? -May contain organic substances such as blood, serum or hemoglobin -May contain special growth factors -Their components are always chemically defined
-May contain organic substances such as blood, serum or hemoglobin -May contain special growth factors
Which of the following are true statements regarding reactive oxygen species (ROS)? -ROS are used by obligate anaerobes instead of O2 -ROS can damage cell components -ROS are commonly found in anaerobic environments -ROS are formed as byproducts of aerobic respiration -ROS are toxic to obligate anaerobes, which typically lack protective mechanisms
-ROS can damage cell components -ROS are formed as byproducts of aerobic respiration -ROS are toxic to obligate anaerobes, which typically lack protective mechanisms
Why is prompt refrigeration of leftover food an effective way to prevent food spoilage? -Refrigeration destroys most microbes that lead to food spoilage and food-borne illness -Refrigeration temperatures are not optimal for reproduction and growth of food-associated pathogens -Refrigeration denatures most toxins that may have been produced by food-associated microbes
-Refrigeration temperatures are not optimal for reproduction and growth of food-associated pathogens
When working with anaerobes, what advantage does an anaerobic chamber give compared to an anaerobe container in terms of the needs of the microbes? -The anaerobe container is cheaper and easier to use, but many more are needed to yield the same space. -The anaerobic chamber gives the researcher the convenience of more space to work -The anaerobic chamber protects strict anaerobes that cannot tolerate even brief exposures to O2
-The anaerobic chamber protects strict anaerobes that cannot tolerate even brief exposures to O2
How are liquid batch cultures most often aerated to support the growth of aerobic microbes? -Air is pumped into the tubes or flasks to supply sufficient O2 -Pure O2 flows under pressure from a gas cylinder into the tubes or flasks to supply maximum O2 -They are grown in tubes or flasks that are shaken continuously
-They are grown in tubes or flasks that are shaken continuously
Why do some microbes require growth factors in their environment? -These are important compounds that enable cells to grow larger -They are unable to synthesize certain necessary organic molecules -Growth factors enable these microbes to grow more quickly
-They are unable to synthesize certain necessary organic molecules
Which of the following correctly describe facultative anaerobes? -They can grow in the presence of O2, but do not use it to harvest energy. -They can grow without O2 -They can only grow in the absence of O2 -Their growth is faster when O2 is available -They grow better if O2 is present
-They can grow without O2 -Their growth is faster when O2 is available -They grow better if O2 is present
Assuming you begin with a single bacterial cell that has a doubling time of 15 minutes, how many cells would you find at the end of one hour? 10 16 4 8 2
16
For many hundreds of years, people have often preserved food by which of the following methods? -Keeping the foods hydrated so they would not dry out -Sealing them raw in airtight containers -Adding large amounts of salt or sugar -Refrigerating them to inhibit microbial growth
Adding large amounts of salt or sugar
Tetanus and gangrene are deep tissue infections associated with tissue damage that limits circulation. With which type of bacteria would you expect these to be associated? Anaerobic Microaerophilic Aerobic
Anaerobic
What term is used to describe organisms that use CO2 as a carbon source? Heterotrophsw Saprotrophs Autotrophs
Autotrophs
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. component of amino acids, lipids, nucleic acids, and sugars
Carbon, oxygen, hydrogen
________________ media work by showing distinct reaction types, such as a color change in some colonies but not in others
Differential
Based on your current understanding of the microbial world, which of the following would you anticipate would need phosphorus? Helminths Bacteria Prions Viroids Viruses
Helminths Bacteria Viroids Viruses
Which of the following describe selective media? -Select for growth of a broad spectrum of organisms -Inhibit the growth of certain species -Display visible differences among microorganisms -Allow the growth of desired organisms
Inhibit the growth of certain species Allow the growth of desired organisms
Selective media are used for which of the following? -Isolating a specific microbe from a mixed population -Growing a broad spectrum of microbes -Growing fastidious microbes only -Differentiating a specific microbe from a mixed population
Isolating a specific microbe from a mixed population
Which of the following relationship describes the optimum temperature of a psychrophile to a thermophile. It is higher than a thermophile. It is the same as a thermophile. It is lower than a thermophile.
It is lower than a thermophile
Complex media contain at least one ingredient that is not chemically defined, such as which of the following? -Tryptophan -Meat extracts -Blood and serum -Sodium chloride -Extracts of animals, plants, or yeasts
Meat extracts Blood and serum Extracts of animals, plants, or yeasts
Consider the following scenario. Unwanted algai blooms in a small lake in Seattle were cleared up by removing excess phosphate from the water. This restricted algal growth. This tells you what about phosphate in this lake? Phosphate is an important source of carbon for algae. Phosphate stimulates growth of algae Phosphate is the limiting nutrient Phosphate is a trace element
Phosphate is the limiting nutrient
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. Component of nucleic acids, membrane lipids, and ATP
Phosphorous
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. Requir3ed for the function of certain enzymes; additional functions as well
Potassium, magnesium, calcium
Which describes the various media that can be prepared for bacterial growth? -They are all similar with respect to their nutrient content -There are few different types -They are diverse in nutrient content and consistency
They are diverse in nutrient content and consistency
Which describes fastidious organisms? -They require the absence of growth factors when grown in culture -They require growth factors and/or complex nutrients -They grow on minimal media -They require simple nutrients when grown in culture
They require growth factors and/or complex nutrients
If you searched around the world, where would you expect to find live prokaryotes? Volcanic vents Inside rocks Within animal hosts Ocean depths Temperatures above boiling Polar regions
Volcanic vents Within animal hosts Ocean depths Temperatures above boiling Polar regions
An _____________ is an organism that prefers acidic pH (pH below 7)
acidophile
A microbe that doesn't use O2 but can grow in environments containing O2 is described as a(n) __________________ anaerobe.
aerotolerant
An __________ is an organism that prefers alkaline pH (pH above 7)
alkaliphile
A(n) _______________ requires only carbon dioxide as a sole carbon source.
autotroph
Which of the following are examples of chemotrophs? bacterial pathogens of humans mammalian cells photosynthetic bacteria fungi algae
bacterial pathogens of humans mammalian cells fungi
Many bacterial communities secrete polysaccharides and other hydrophilic polymers. This mesh-like accumulation can help protect the bacteria growing within from antibiotics or disinfectants. These communities are called _____________
biofilms
You are setting up an enrichment culture to look for bacteria that can use phenol as a carbon source. In your medium, you provide a variety of major elements and trace elements, plus phenol. Other than that contained in the phenol, what must you avoid adding if you hope to enrich for phenol-degraders? carbon potassium nitrogen iron phosphorus
carbon
Which of the following are considered major elements that make up cell constituents? -carbon -copper -phosphorus -hydrogen -nitrogen -molybdenium -oygen -cobalt
carbon phosphorus hydrogen nitrogen oxygen
The enzyme ___________ converts hydrogen peroxide formed during aerobic respiration to water and O2.
catalase
Ingredients that could be in complex media but not chemically defined media include which of the following? sodium chloride cell secretions extracts of animals, plants, or yeasts blood and serum disodium hydrogen phosphate
cell secretions extracts of animals, plants, or yeasts blood and serum
Match the following groups of prokaryotes according to the energy and carbon sources they utilize. Energy: inorganic chemicals; Carbon: CO2
chemolithoautotroph
Bacteria that rely on inorganic compounds to supply their energy needs and derive their carbon from CO2 are known as ____________
chemolithoautotrophs
Which type of microorganism derives nutrition from organic compounds? photoautotroph chemoorganoheterotroph chemolithotroph
chemoorganoheterotroph
Match the following groups of prokaryotes according to the energy and carbon sources they utilize. Energy: organic compounds; Carbon: organic compounds
chemorganoheterotroph
Which term describes organisms which acquire their energy from chemical compounds? phototrophs autotrophs chemotrophs
chemotrophs
____________ media are designed to show detectable differences in colony appearance among various species of microorganisms
differential
Media designed to highlight distinguishing characteristics of different organisms are called which of the following? -selective media -special media -differential media -specific media
differential media
Certain members of the Archaea require 9% or greater concentrations of sodium chloride and are found growing in locations such as the salt flats of Utah and the Dead Sea. These microbes are termed ________ __________
extreme halophiles
True or False: Selective media cannot be differential
false
Bacteria that require growth factors and complex nutrients are termed _____________
fastidious
Bacteria that require growth factors and complex nutrients are termed ______________
fastidious
Bacteria, such as Neisseria species, that require numerous growth factors in order to grow are termed ________________
fastidious
What term is used to describe the amount of time a particular microbial species takes to double in number? Growth time mitosis time generation time binary fission
generation time
A ___________ factor is an organic compound, such as a vitamin or an amino acid, that a given microorganism cannot synthesize and therefore must be provided in the growth medium.
growth
If a microbe is unable to synthesize certain organic molecules such as amino acids, vitamins, purines, or pyrimidines, these ________ __________ must be available in the environment in order for the microbe to grow
growth factors
An extreme _____________ specifically requires a high concentration of salt for growth
halophile
Bacteria, such as Staphylococcus, that can tolerate high salt concentrations such as those found on human skin are ________________
halotolerant
An organism that must consume organic matter is called a(n) ___________
heterotroph
If a microorganism has a temperature optimum close to the boiling point of water, it is considered a ______________. -thermophile -hyperthermophile -psychrotroph -mesophile -extremophile -psychrophile
hyperthermophile extremophile
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. Part of certain enzymes
iron
Match the term on the left with the description of the optimum temperature environment. human body
mesophile
Match the term with the description of the optimum temperature environment. human body
mesophile
With regard to their temperature requirements, medically important microorganisms are typically _________________ because they have evolved to thrive in or on the human body.
mesophilic
A microbe that requires small amounts of O2 (2-10%) for aerobic respiration but is inhibited by higher concentrations is called a(n) __________________. microaerophile obligate aerobe aerotolerant anaerobe facultative anaerobe
microaerophile
A ____________ requires reduced concentrations of O2 in the range of 5-15%
microaerophilic
What name is given to microbes that prefer environments near or at a pH of 7?
neutrophile
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. component of amino acids and nucleic acids
nitrogen
Unlike sugar, proteins provide which of the following elements? hydrogen oxygen carbon nitrogen
nitrogen
A(n) _______________ aerobe, or strictly aerobic organism, requires O2 for survival
obligate
Bacteria that cannot multiply if O2 is present, and are often killed by even brief exposure to air, are termed ___________ ___________
obligate anaerobes
Animals could not survive without autotrophs because without them the world would run out of ______________. inorganic carbon inorganic nitrogen organic carbon organic nitrogen
organic carbon
Which of the following gases is found at about 20% of the Earth's atmosphere? carbon dioxide nitrogen oxygen methane
oxygen
An autotrophic organism that uses light energy and carbon dioxide as a carbon source is termed a ______________.
photoautotroph
Match the following groups of prokaryotes according to the energy and carbon sources they utilize. energy:sunlight; carbon: CO2
photoautotroph
Match the following groups of prokaryotes according to the energy and carbon sources they utilize. energy: sunlight; Carbon; organic compounds
photoheterotroph
A _______________ is an organism that obtains energy directly from sunlight.
phototroph
If the solute concentration is higher outside the cell than inside the cell, water will diffuse out due to osmosis. This will result in ____________.
plasmolysis
Match the term with the description of the optimum temperature environment. cold Artic regions
psychophile
Match the term with the description of the optimum temperature environment. refrigeration
psychotroph
Match the term on the left with the description of the optimum temperature environment. cold Arctic regions
psychrophile
Match the term on the left with the description of the optimum temperature environment. refrigeration
psychrotroph
Which term describes a microorganism that has an optimum temperature between 20 and 30 degrees C but thrives and divides under refrigeration conditions? mesophile thermophile psychrotroph
psychrotroph
Microbial cells must maintain a near-neutral internal pH. Because of this, bacteria that grow in acidic environments have mechanisms to -pump out protons that enter the cell -bring protons into the cell
pump out protons that enter the cell
MacConkey agar contains bile salts and dyes that inhibit Gram-positive organisms and Gram-negative cocci making it ____________; it also contains a pH indicator that turns pink-red when lactose in the medium is fermented, making it ________________
selective; differential
Consider the major elements that make up cell constituents. Match the correct major elements with the representative functions shown. component of some amino acids
sulfur
Match the term on the left with the description of the optimum temperature environment. compost heap
thermophile
Match the term with the description of the optimum temperature environment. compost heap
thermophile
Microorganisms which prefer hot environments (optimum temperatures 45 to 70 degrees C) are termed _________________
thermophiles
Cobalt, zinc, copper, molybdenum, and manganese are all examples of _______ ___________
trace elements
Substances like zinc, manganese, and nickel are called __________ necessary elements macronutrients trace elements
trace elements
True or false: Many medically important bacteria (ex: species of Neisseria and Hoemophilus) grow best in aerobic atmospheres that have additional CO2
true
Environmental factors that influence microbial growth include: water availability temperature pH oxygen availability humidity
water availability temperature pH oxygen availability