Microbiolgy

Members of the genera Bacillus and Clostridium ______.

produce dormant cells called endospores

All of the following are examples of means by which microorganisms can respond to changing environmental conditions EXCEPT

production of different ribosomes

When boiling or pasteurizing a sample, microorganisms are destroyed because their ______.

proteins are irreversibly denatured

None of the Archaea have peptidoglycan in their cell walls. However, some have a similar molecule called

pseudopeptidoglycan

Microbial cells must maintain a near-neutral internal pH. Because of this, bacteria that grow in acidic environments have mechanisms to ______.

pump out H+ that enter the cell

A(n) ______ culture contains only ONE species of microorganisms descended from a single cell.

pure

Cells duplicate their DNA before cell division using a process called DNA

replication

Suppose that the concentration of an ion is higher in the cytoplasm than in the extracellular environment. If the bacterium wants to bring in more of that ion into the cell, which description best describes this type of transport?

requires energy from the cell, moves against the concentration gradient

Compounds that interfere with the synthesis or structural integrity of peptidoglycan can ______.

result in bursting of a bacterial cell

RNA contains the sugar _____, which differs from its DNA counterpart by possessing _____ oxygen atom.

ribose; one more

The joining of amino acids to synthesize proteins is facilitated by cytoplasmic structures called

ribosomes

A medium that contains an ingredient that inhibits the growth of some bacteria, while allowing others to grow, is called a(n) _____ medium.

selective

The cytoplasmic membrane is a(n) ______ permeable barrier of the cell.

selective

Medical instruments are classified into three categories according to their risk for transmitting pathogens. These are: critical instruments, _____ instruments, and ______ instruments.

semicritical; noncritical

The function of mRNA is to

serve as a template for protein synthesis

In a bacterium, pili are typically _______ than flagella.

shorter but more numerous

The transmission of information from outside a cell to the inside is known as

signal transduction

Which metal compound is used as a disinfectant in burn creams and bandage pads?

silver

A procedure that requires the use of a single dye to stain a specimen is called ______ staining

simple

Which of the following staining procedures requires the use of only a single dye?

simple staining

All of the following are examples of electromagnetic radiation EXCEPT _____

sound waves

______ destroy all microbes, including viruses and endospores.

sterilants

A photoautotroph obtains energy from ______ and carbon from ______ in order to make organic compounds.

sunlight; CO2

Ribosomes are directly involved in ______.

the synthesis of proteins

All of the following statements about immunofluorescence are true except one. Which?

uses the dye methylene blue

If you want to determine the proportion of cells that have been killed by a particular antimicrobial treatment, it would be best to do which type of cell count before and after that treatment?

viable cell count

Light microscopes that are routinely used in the laboratory can magnify images about _______.

1,000X

Which of the following are eukaryotes?

1. Algae 2. Helminths 3. Protozoa 4. Fungi

Controlling microbial growth is important in which of the following scenarios?

1. Caring for an open wound 2. Preparing a patient for surgery 3. Manufacturing of food products

Unlike a stained specimen, living moving cells can be observed using a(n) __________ mount.

wet

When observing live organisms, the specimen is prepared with a drop of liquid on which a coverslip has been placed. This is called a _______ ______

wet mount

What is the principal function of mitochondria?

ATP production

From which body site could a facultative anaerobe be isolated?

Any of these locations

What term is used to describe organisms that use CO2 as a carbon source?

Autotrophs

Peptidoglycan provides strength to the cell walls of ______.

Bacteria

What term is used to describe a group of microbes co-existing in polymer-encased communities?

Biofilm

Which type of microscope transmits a light through a specimen in order to illuminate the field of view evenly?

Bright-field microscope

Which of the following best describes how the atmospheric needs of aerobic microbes can be met?

By growing them in the air.

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

There is a standard antimicrobial procedure available from the Centers for Disease Control and Prevention (CDC) that can be used for all different microorganisms under any condition.

False

_______ is a physical means used for destroying or removing microorganisms.

Filtration

The motility of bacteria is typically facilitated by long appendages called

Flagella

The __________ microscope is a specially modified light microscope that uses an ultraviolet light source.

Fluorescence

What is the outcome if translation begins at the wrong reading frame?

Generally, a non-functional protein is made.

For the name Streptococcus pyogenes, the first part (Streptococcus) indicates the ________ and gives information about the shape of the organism.

Genus

Which of the following organelles typically receives and then modifies proteins from the endoplasmic reticulum before they are transported to other destinations?

Golgi apparatus

The ______ stain is the most widely used staining procedure for distinguishing different groups of bacteria.

Gram

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

What term is used to describe essential organic compounds, such as a vitamin or amino acid, that must be provided in the diet?

Growth factors

Which of the following is true regarding all prokaryotes?

Lack a nucleus

_______ is credited with disproving spontaneous generation using broth in swan-neck flasks.

Louis Pasteur

______ are membrane-bound organelles that contain digestive enzymes, which degrade materials taken up by the cell and participate in autophagy.

Lysosomes

How do electron microscopes differ from light microscopes?

Magnification is higher

What term is used to describe chemical substances such as carbon or phosphorous, which are found in large quantities in cells?

Major element

Algae and protozoa are also referred to as _______, a diverse group that falls within the domain Eukarya.

Protists

What enzyme binds to a DNA promoter region to initiate transcription?

RNA polymerase

During transcription, RNA polymerase synthesizes ______ from a(n) ______ template.

RNA; DNA

Transcription is carried out by an enzyme called ____ ______

RNA; polymerase

What are the three major structures directly involved in translation?

Ribosomes, mRNA and tRNA

Which environment is more dynamic and complex?

Soil and its surroundings

Why are cells sometimes difficult to see in a wet mount?

Some move quickly. Some are transparent.

The concept of living things arising from vital forces in non-living or decomposing materials was known as which of the following?

Spontaneous generation

Following treatment to remove all viable microorganisms, including viruses, an object is considered to be

Sterilization

Imagine you are a microbiologist trying to isolate new species of prokaryotes. You collect numerous samples and return to your lab, where you proceed to encourage any prokaryotes present to grow. Disappointingly, you are not successful. Which is the LEAST likely explanation for this outcome?

There were no prokaryotes present where you sampled.

How might an enrichment culture be used to isolate organisms capable of nitrogen fixation?

Using a media that does not contain any form of nitrogen, and exposing it to the atmosphere

Cervical cancer caused by the human papillomavirus (HPV) can be prevented by a(n) ______.

Vaccine

Unlike the term microorganism, the word microbe also includes ______.

Viruses

Which of the following about microorganisms is true?

We could not survive without them.

A replication fork is ______.

a Y-shaped structure where both DNA strands are being replicated

The capsule stain shows the capsule as ______.

a clear area surrounding a cell

Compared to an electron microscope, the atomic force microscope has ______.

a higher resolving power and does not require special sample preparation

If O2 is present in an environment, it is said to be _______.

aerobic

Which of the following chemical classes destroy microorganisms by forming chemical bonds that cross-link and inactivate proteins and nucleic acids?

aldehydes

A sterile object is free of ______.

all viable microorganisms and viruses

An environment with little or no O2 present is called a(n) ____ environment.

anaerobic

mmunofluorescence uses a(n) ____ that has a fluorescent compound to tag a specific protein.

antibody

A tRNA has a(n) _______, Incorrect Unavailable, a group of three nucleotides that is complementary to the codon of the mRNA.

anticodon

Some microorganisms can alter characteristics of certain surface proteins, allowing them to avoid detection by the host's immune system. This phenomenon is called ______.

antigenic variation

The five groups used to categorize microorganisms with respect to growth temperature (psychrophile, psychrotroph, mesophile, thermophile, and hyperthermophile) ______.

are based on optimum growth temperatures.

It is often difficult to choose which germicide to use because often the most effective options ______.

are not the safest

A(n) ________ force microscope uses a very sharp scanning probe to produce detailed images of surfaces with a very high resolving power.

atomic

_______ are accumulations of high-molecular weight polymers synthesized from a nutrient that a cell has in relative excess.

atorage granules

When bacteria or archaea are grown on agar plates or in tubes or flasks of broth, these closed systems are a ______ culture. By contrast, cells can also be grown in an open system, or a continuous culture.

batch

Bacteria and archaea typically divide by a process known as _____ ______

binary; fission

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

What type of staining is used to observe the gel-like layer that surrounds certain microbes?

capsule

Adding sorbic, propionic, and benzoic acid to foods affects ______ of microbes.

cell membrane function

Peptidoglycan is found in the ______.

cell walls of bacteria

Viable cell counts determine the number of ______.

cells capable of multiplying

The cytoplasmic membrane of prokaryotic cells plays a crucial role in transforming energy. This means that the membrane is directly involved in ______.

converting the energy of sunlight or food into ATP

In recent years, a new field of bioinformatics has emerged, which ______.

creates the computer technology to store, retrieve, and analyze nucleotide sequence data

A surgical scalpel is rated as a ______ instrument because it penetrates skin and mucous membranes and therefore must be sterile.

critical

All cells have a _____ membrane, also called the cell membrane or the plasma membrane.

cytoplasmic

A flexible molecular framework throughout the cytoplasm that anchors organelles and permits shape changes in some cells is called the

cytoskeleton

Previously it was thought that bacteria lacked a(n) _____, a network of interior proteins that provides support and structure to the eukaryotic cell. Recently though, similar proteins have been characterized in bacteria.

cytoskeleton

In order to detect bacteria growing in patient blood samples, clinical labs can use a fluorescent sensor to detect the slight ______ in pH that accompanies the production of carbon dioxide.

decrease

What is the main function of lysosomes?

degradation

Bacteria growing in a natural environment experience ______.

dynamic and complex conditions

Radio waves, X-rays, microwaves, UV light and gamma rays are all examples of ______.

electromagnetic radiation

An electron microscope uses a beam of electrons, which is focused by _______ lenses, to generate a magnified image on a _______ screen.

electromagnetic; fluorescent

Eukaryotic cells use the process of ______ to take in substances too large to move through a transport protein.

endocytosis

Pinocytosis and phagocytosis are two of the three examples of

endocytosis

The _______ of eukaryotic cells is a complex system of flattened sheets, sacs, and tubes.

endoplasmic reticulum

The most highly resistant microbial structure is the bacterial

endospore

Some secreted proteins will act as ______ outside of the cell and catalyze the breakdown of large macromolecules.

enzymes

The work of John Tyndall and Ferdinand Cohn ______.

explained why some spontaneous generation investigators got different results from those of Pasteur

Some microorganisms live in harsh environments that kill most other organisms. The term used to describe an organism with this characteristic is

extremophile

A codon and an anticodon base pair with each other because they have identical nucleotide sequences.

false

An RNA transcript is a strand of RNA copied from an RNA template.

false

Choosing which germicide to use is not that complicated since we only consider how effective it is against the target microbes.

false

There is a standard antimicrobial procedure available from the Centers for Disease Control and Prevention (CDC) that can be used for all different microorganisms under any condition.

false

The straining of a fluid or air through a membrane to trap microorganisms is known as

filtration

______ does not actually destroy microbes or inhibit their growth but instead removes them physically from samples.

filtration

A common dry heat sterilization method used in the microbiology laboratory is ______.

flaming the inoculating loop

Which of the following microscopes exposes specimens to ultraviolet light and forms an image with the light emitted at a different wavelength?

fluorescence microscope

Small, rigid, protein-bound compartments that provide buoyancy to some aquatic bacterial cells are called _____ vessicles.

gas

A ______ is a sequence of nucleotides that usually codes for one functional protein.

gene

The ______ _____ correlates a series of three nucleotides to one amino acid or a stop codon.

genetic code

Phenolics are ______.

germicidal

If a cell has a nutrient in relative excess, it may accumulate that compound in a storage

granule

A graphical representation of a changing population size over time is called which of the following?

growth curve

The characteristic pattern that shows the changes in size of a bacterial population over time in a broth culture is called a bacterial ______ _______

growth; curve

Chlorine and iodine are common disinfectants that belong to a class of chemicals called

halogens

Salting and drying decrease the availability of water in food, resulting in an environment that is ______ relative to microbes, thereby preventing their growth.

hypertonic

A testable explanation for an observation is called a(n)

hypothesis

Hydrogen peroxide is a more effective germicide on ______.

inanimate objects

Eukaryotic cells can regulate the levels of mRNA by destroying specific RNA transcripts through a process known as RNA ______ abbreviated RNAi.

interference

Ozone ______.

is a strong oxidizing agent

Ethylene oxide is gaseous agent that ______.

is very useful for sterilizing heat- or moisture-sensitive items

All of the following are characteristics of bleach, a solution of sodium hypochlorite, EXCEPT ______?

it is only effective against a limited range of microorganisms

A light microscope uses visible light and a series of ______ to magnify objects

lenses

Microorganisms that are free living are ______ to chemical disinfectants than microorganisms in a biofilm.

less resistant

Bacteria use gas _____ vesicles to float to the surface of water to better access as a source of energy.

light

A solution of sodium hypochlorite is more effective against bacteria at _______ pH.

low

is transcribed from a DNA template and translated during protein synthesis.

mRNA

Carbon, oxygen, hydrogen, nitrogen, sulfur, and phosphorus, are examples of chemical substances called _____ _____ which are the essential components of the cell's macromolecules.

major; elements

Soap generally does not destroy most microbes, but it aids in their ______.

mechanical removal

Washing hands with plain soap and water works by ______ removing microbes.

mechanically

Organisms that populate the human body and which protect it from disease are termed normal

microbiota

Household bleach applied at 55C is ________ effective in killing bacteria than if it were applied at 50

more

Phenolic compounds are effective against ______.

most vegetative bacterial cells

All DNA nucleotides contain the same deoxyribose and phosphate groups, but different

nucleases

In eukaryotic cells, the genetic material is found in the

nucleus

The most significant structural difference between eukaryotic and prokaryotic cells is the presence or absence of a membrane-bound _______, which contains the genetic material

nucleus

A(n) ______ aerobe, or strictly aerobic organism, requires O2 for survival.

obligate

A species grows most rapidly at its ______ growth temperature

optimum

To initiate replication of a DNA molecule, specific proteins must bind to a specific DNA sequence called the ______.

origin of replication

The effectiveness of hydrogen peroxide as a germicide on living tissue like wounds is reduced because ______.

our catalase enzymes quickly break it down

Which of the following is a component of Gram-negative cells but not Gram-positive cells?

outer membrane

Used as an alternative to chlorine for disinfecting water, _____ is a strong but unstable oxidizing agent that must be generated on-site, usually be passing air or O2 between two electrodes.

ozone

Some microorganisms produce acids during metabolism. Which of the following would be a strong indication of this activity?

pH of the culture medium should be lower after growth

A(n) _____ is the term used for any disease-causing microorganism.

pathogen

The strength of the bacterial cell wall is due to the layer of

peptidoglycan

The ability of Escherichia coli to randomly turn on or off the the production of attachment pili is an example of

phase variation

What is the active ingredient in Lysol?

phenolics

The cytoplasmic membrane is a(n) ____ bilayer embedded with _____

phospholipids; proteins

An autotrophic organism that uses light for energy and carbon dioxide as a carbon source is termed a

photoautotroph

Heat treatment, irradiation and filtration are examples of ______ used to control microorganisms.

physical processes

A high-solute environment damages microbial cells by causing ______.

plasmolysis

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

The Gram stain separates bacteria into two major groups called _______, based on the structure of their _______.

positive and negative; cell walls

The act of delaying spoilage is ______.

preservation

High- _____ processing (HPP) is used to decrease the number of microbes in food while maintaining the color and flavor.

pressure

Which of the following describes how fungi gain energy?

They degrade organic materials.

Plague is a _______.

bacterial disease that can be transmitted by fleas

Penicillin interferes with the synthesis of peptidoglycan, and lysozyme degrades peptidoglycan. Based on this information, you can conclude that penicillin and lysozyme may result in bursting (lysing) of which type of cells?

Bacterial

Which of the following are manufactured by microbial fermentation?

Beer, cheese, yogurt

Why do microorganisms serve as important models for study of higher organisms?

Microorganisms have the same fundamental metabolic and genetic properties as other organisms.

Cells that do not have a membrane-bound nucleus are called _____ cells

Prokaryotic

We could not survive without microorganisms, but they can also be harmful.

True

Rank the steps in the scientific process in order. Start with the earliest at the top.

1. Make an observation about something and ask a question about the situation. 2. Develop an explanation and then devise an experiment to test this explanation 3. collect data from this experiment and draw a conclusion 4. Communicate the methods, results, and conclusions

What does the scientific name of an organism include?

genus and species

Which of the following are classified as acellular infectious agents?

1. viruses 2. prions 3. viroids

he principle that microorganisms cause certain diseases is called the ______ Theory of Disease.

Germ

Which defines spontaneous generation?

Life arose from non-living matter.

Most bacteria have rigid cell walls that contain a unique compound called

Peptidoglycan

Some bacteria are covered with a substance that creates a diffuse irregular layer called a ______ ______

Slime; layer

What is the only shared feature of all microbes?

Small size

Although laboratory stocks of the causative agent still exist, humans have eliminated which of the following diseases?

Smallpox

All of the following statements about smallpox are true except one. Which?

Smallpox is caused by bacteria

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.

Penicillin is ineffective against Mycoplasma species because the organism lacks a rigid ____ ____

cell; wall

Technically speaking, viruses are not microorganisms because they are not ______.

composed of cells

Archaea, like bacteria, are single-celled ____ that divide via the process of ____ ____

prokaryotes; binary; fission

The cytoplasmic membrane of prokaryotes is composed of a(n) _____ bilayer embedded with proteins.

phospholipid

In addition to chlorophyll, some algae have other ______ , which give them their characteristic colors.

pigments

Which of the following are microscopic fungi?

yeasts and molds

The prokaryotic cell envelope consists of which of the following?

1. cell wall 2. cytoplasmic membrane 3. capsule

A distinct and gelatinous layer surrounding a cell is called a ______.

Capsule

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

Membrane-bound organelles are only found in the cell type called a(n) ______ cell

Eukaryotic

_______ showed that flasks containing various broths gave rise to microorganisms even when the flasks were boiled and sealed with a cork.

John Needham

Which two macromolecules are the major components of cytoplasmic membranes?

Lipids and proteins

In general, disease-causing organisms are referred to as which of the following?

Pathogens

Active transport moves compounds against their concentration gradient. The form of energy used for this purpose is either ______ or the _____ _______ force.

ATP; proton; motive

_______ are a large group of photosynthetic eukaryotes that includes the multicellular seaweeds and many single-celled forms.

Algae

Organisms living today ______.

Can be classified into three domains

Which of the following statements about the influenza pandemic of 1918-1919 is true?

More Americans died of influenza in 1918-1919 than were killed in World Wars I and II, and the Korean, Vietnam, and Iraq wars combined.

Today, the bacteria added to some fermented milk products are advertised as _______.

Probiotics

Which two macromolecules are the major components of cytoplasmic membranes?

Proteins and lipids

Many members of the Archaea have ____-______ , which are sheets of flat proteins or glycoprotein subunits.

S; layers

An infectious disease that has become more common in the last several decades is referred to as a(n) ______ infectious disease

emerging

The Germ Theory of Disease states that ______.

microorganisms cause certain diseases

The function of the cell wall is to ______.

prevent the cell from bursting

As important decomposers, fungi obtain nutrients by ______.

secreting enzymes to degrade organic material in the environment

Cells use a process called _______ to move certain enzymes and other proteins they synthesize out of the cell.

secretion

The microbial world includes three main agents that cannot reproduce independently and are thus considered non-living. These are the ______, ______, and _______

viruses, viroids, prions

Emerging infectious diseases are those ______.

whose incidence has rapidly increased in the last several decades

Microscopic fungi that are single-celled are called ______, and that that are multicellular and filamentous are termed _______.

yeasts; molds

Without microorganisms, substances required for human life such as O2 and organic nitrogen would ______.

run out

Vaccinations have helped reduce the spread of mumps, measles and whooping cough in developed countries.

True

A typical bacterium possesses ______.

a single, circular chromosome

_______ killed more people in 1918-1919 than died in World Wars I and II and the Korean, Vietnam, and Iraq wars combined.

Influenza

Fungi are a diverse group of eukaryotes. Those that are studied by microbiologists include the unicellular ______ and the multicellular filamentous ______.

yeasts; molds

Cervical cancer caused by the human papillomavirus (HPV) can be prevented by a(n) ______.

vaccine

In eukaryotes, the genetic material is contained within a membrane-bound structure called the

Nucleus

Which of the following diseases killed one-third of the population of Europe in a four-year span (1347-1351)?

Plague

Enzymes that are synthesized constantly in a cell are called

constitutive

The term that describes the appearance of a cloudy broth culture is

turbidity

_______ describes the cloudiness or haziness of a fluid.

turbidity

An organism that gets its energy directly from sunlight is called a(n)

Phototroph

Why are cells growing in a colony on solid media likely to be in many more different phases of growth than cells growing in liquid culture?

1. Cells in liquid culture experience a relatively uniform environment, so they are much more likely to be in the same phase of growth. 2. Unlike cells on the edge of a colony, those in the center of a colony face depleted levels of nutrients and O2, yielding different phases of growth.

A batch culture has which of the following characteristics?

1. It typically involves growth of bacteria or archaea either on agar plates or in tubes or flasks of broths. 2. Wastes are not removed. 3. Nutrients are not renewed. 4. It is a closed system.

Which four of the following microbial groups are the most resistant to chemical control methods?

1. Mycobacterium species 2. protozoan cysts and oocysts 3. bacterial endospores 4. nonenveloped viruses

High pressure (130,000 psi) is thought to kill microbes by altering their ______.

1. cell membranes 2. proteins

Phenolics kill microorganisms by ______.

1. destroying cytoplasmic membranes 2. denaturing proteins

Although generally less reliable than heat, germicidal chemicals are especially useful for treating ______.

1. large surfaces 2. heat-sensitive items

Consider the following environmental factors. Which have the most impact on microbial growth?

1. water availability 2. pH 3. atmosphere 4. temperature

How many replication forks are formed from opening a section of a circular DNA molecule as part of DNA replication?

2

A codon contains how many nucleotides?

3

What is the proper order of the following events in the expression of a eukaryotic gene?1. translation2. RNA processing3. transcription

3, 2, 1

Aqueous solutions of alcohol at a concentration of ______ are more effective than 100% alcohol.

60%-80%

In eukaryotes, a cytoplasmic ribosome has a size of ______, and is made up of a small 40S subunit and a large ______ subunit.

80S; 60S

Why is regulation of gene expression important?

A cell does not need all of its encoded proteins at the same time.

When preparing a wet mount specimen for viewing, what should be placed on top of the specimen?

A coverslip

Which of the following is most likely to be a pure culture?

A single colony growing on a streak plate.

Which of the following describes the termination of translation?

A stop codon is reached and the polypeptide is released from the ribosome.

If both glucose and lactose are present in a medium, why is the lac operon not transcribed?

Cells preferentially use glucose and only use lactose if the glucose is depleted.

In plant and algae cells, __________ are organelles that contain pigments for photosynthesis.

Chloroplast

Which organelle is the site of photosynthesis?

Chloroplast

The bacterial _____ is typically a single, circular, double-stranded DNA molecule that contains all of the essential genetic information required by a cell.

Chromosome

Which of the following does not describe interactions of mixed microbial communities?

Conditions in mixed microbial associations are readily reproduced in the laboratory.

What collective name is given to the various proteins that criss-cross the cell's interior, hold various organelles in place, enable movement of intracellular structures, and give the cell internal structural integrity?

Cytoskeleton

What internal structure helps control cell shape and is involved in cell division?

Cytoskeleton

An essential macromolecule that encodes all of the information needed by a cell to synthesize its components is

DNA

The molecule that encodes all the instructions needed to produce a cell's components is ______.

DNA

All living organisms are now classified into three different taxonomic units called

Domains

Tyndall and Cohn's experiments in the 1870s showed the presence of a heat-resistant form of bacteria called a(n)

Endospore

The surface layers of a prokaryotic cell are collectively referred to as the cell _______.

Envelope

oxide is an extremely useful gaseous sterilizing agent that destroys all microbes and is often used to sterilize fabric, equipment, and implantable devices.

Ethylene

Which type of organism requires organic compounds for its carbon and energy needs?

Heterotroph

_______ is the destruction of microbes by subjecting them to extremes of dry heat, reducing them to ashes.

Incineration

______ provides an alternative to heat for sterilization and disinfection, but the process damages some types of plastics.

Irradiation

Which of the following describes the optimum temperature of a psychrophile relative to a thermophile?

It is lower than a thermophile.

Which is the best general description of a medium used to support bacterial growth in a Petri dish?

It may have very few nutrients, or it may have many different nutrients to support widely varying growth requirements.

_____ function as ATP-generating powerhouses and are found in nearly all eukaryotic cells.

Mitochondria

Compared to the range of types of plants and animals, microbes as a group are ______.

More diverse

Bacteria of the genus _______ do not have cell walls, and so they are naturally resistant to the antibiotic _______.

Mycoplasma; penicillin

Which of the following describes a microbe that must have O2 to survive?

Obligate aerobe

Which describes the various laboratory media used to cultivate bacteria?

They are diverse in nutrient content and consistency.

How are liquid batch cultures most often aerated to support the growth of aerobic microbes?

They are grown in tubes or flasks that are shaken continuously.

Benefits of normal microbiota include all EXCEPT which of the following?

They damage host tissue, allowing our immune system to rid the body of microbes

A direct cell count determines the number of ______ in a sample

Total cells

A colony is a distinct mass of microorganisms which develop from a single cell growing on a solid medium.

True

Although eukaryotic flagella and cilia appear to project out of the cell, they are covered by extensions of the cytoplasmic membrane.

True

Bacterial components unique to bacteria are potential targets for antibacterial medications used to treat infectious diseases.

True

Eukaryotic cells have a nucleus, which contains the cell's genetic information.

True

Some species of microorganisms can be found in environments where no unprotected human could survive.

True

The risk of developing a fatal infection after surgery has substantially decreased since the late 19th century because modern hospitals now have procedures in place to avoid microbial contamination.

True

Which device is used to keep cells in a state of constant growth?

chemostat

In algae, photosynthesis takes place in ______, which have chlorophyll, a green pigment.

chloroplasts

In general, the chromosome of a bacterial cell is a _______ DNA molecule that is replicated _______.

circular; bidirectionally from one origin of replication

The two most common examples of endospore-forming genera are ____ and ______.

clostridium; bacillus

A(n) _____ is the specific sequence of three nucleotides in mRNA that encode a particular amino acid or a stop signal.

codon

An isolated ______ is a distinct mass of microorganisms appearing on a solid medium, arising from the multiplication of a single cell.

colony

Eukaryotic flagella and cilia are ______.

composed of long microtubules flexible structures

Enzymes involved in essential metabolic pathways, such as glycolysis, are usually

constitutive

Microorganisms must adapt rapidly to changes in their environment in order to

survive

Which type of RNA carries amino acids during protein synthesis?

tRNA

When selecting an appropriate chemical disinfectant, it is important to realize that the death rate is significantly influenced by ______ and ______.

temperature; pH

What is one disadvantage of using heat treatment to sterilize plastic items?

the items may melt

Which of the following is found in all DNA nucleotides?

the same sugar and phosphate, but different nucleobases

The cell wall of Gram-positive bacteria is characterized by ______.

thick layer of peptidoglycan

An mRNA sequence has ______.

three potential reading frames, but only one is typically used for translation

Alternative sigma factors allow cells to directly control

transcription

Information is passed from the environment into the cell by a process known as signal

transduction

During what process is the information in mRNA used to make a protein?

translation

_______ is the process of decoding the information carried by mRNA to synthesize a protein.

translation

A bright-field microscope ______.

transmits light through a specimen

A colony is a distinct mass of microorganisms which develop from a single cell growing on a solid medium.

true

DNA replication must occur prior to cell division to ensure that each new cell has a complete genome.

true

Regulating gene expression involves controlling mRNA synthesis and rapidly destroying mRNA transcripts.

true

Chlorine-releasing compounds such as sodium hypochlorite (bleach is a 5.25% solution) are used for all of the following EXCEPT ______.

wound treatment and skin cleansing

What long protein structures are responsible for most types of prokaryotic motility?

Flagella

Compounds unique to bacteria or certain other microbial groups can be detected by "alarm systems" in the body.

True

Microorganisms are useful in the study of higher life forms for which of the following reasons?

1. Microorganisms have the same fundamental genetic properties 2. Microorganisms have the same basic metabolic mechanisms 3. microorganisms multiply quickly 4. microorganisms are cheaper to study

In what ways are archaea similar to bacteria?

1. energy sources used 2. method of multiplication 3. shapes and sizes 4. prokaryotic cell structure

Which of the following can be characteristics of algae?

1. multicellular 2. eukaryotic 3. unicellular 4. photosynthetic

Which of the following can cause an infectious disease to reemerge?

1. parents refusing to vaccinate their children 2. pathogens becoming resistant to antimicrobial medications

Which of the following molecules can freely pass through the phospholipid bilayer?

1. water 2. CO2 3. O2 4. small hydrophobic compounds

Without microorganisms, we would run out of certain nutrients.

True

Because they are often caused by a Helicobacter pylori infection, most stomach ulcers are treatable with ______.

Antibiotics