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