micro cumulative final review Flashcards

All cellular organisms are classified as

A. Bacteria

B. Archaea

C. Eukarya

Protists contain all of the following forms of life except

A.protozoa

B.fungi

C.slime molds

D.algae

E. amoeba

True or False: Viruses are not generally studied by microbiologists because they are not classified as living organisms

True or False: Prokaryotes have a relatively complex morphology and a true,membrane-delimited nucleus.

Which of the following distinguish the field of microbiology from other fields of biology?

A.The size of the organism studied.

B.The techniques used to study organisms regardless of their size.

C.Both the size of the organism studied and the techniques employed in the study of organisms.

D.Neither the size of the organism studied nor the techniques employed in the study of organisms regardless of their size.

The concept that living organisms arise from nonliving material is called

__was the first to observe and accurately describe microorganisms.

Redi’s experiment included both a dish of meat covered with cheesecloth and an uncovered dish of meat to show

A. maggots did not appear under any circumstances

B. spontaneous generation would occur if the air could get to the meat

C. that maggots would only appear if flies had access to the meat

D. that bacteria would not grow on the meat

E. air was necessary to produce maggots

The first step in using Koch’s method for determining the organism causing disease is to:

A. Observe the organism in sick animals, but not healthy ones

B. Isolate the different organisms in sick animals, and inject them into healthy subjects

C. Identify the species of the organisms infecting sick animals

D. Grow each organism in pure culture

E. Observe the same disease in animals injected with the purified organism

True or False: Although developed over 100 years ago, Koch's postulates continue to be used successfully in all known human infectious diseases.

True or False: All microorganisms can be grown on nutrient agar plates

If you are working in a laboratory and wish to create a pure culture of a virus, which of the following would best allow you to do this?

A. A nutrient agar plate with LB media.

B. A tube of nutrient media broth.

C. A flask of living cells and nutrient media.

D. All of the above would allow you to do this.

E. None of the above as viruses cannot be cultured in the lab.

The branch of microbiology that deals with the mechanisms by which the human body protects itself from disease-causing organisms is called _____

__ microbiology involves the use of microorganisms to make products such as antibiotics, vaccines, steroids, alcohols, vitamins, amino acids, and enzymes.

True or False: . When looking through a compound microscope at an image, the visual image seen is actually upside down

18. What is the purpose of a lens in a microscope?

A. To focus light rays at a specific place called the focal point.

B. To bend and refract light waves away from a specimen on a slide.

C. To provide a light source under a specimen.

D. To improve resolution of the image through adjustments of the stage.

E. To measure the ability to gather light and resolve fine specimen detail at a fixed object distance

The _____________ is a measure of how greatly a substance slows the velocity of light.

A. reflective index

B. condensing power

C. refractive index

D. resolving powe

rE. condenser

Which of the following would provide the greatest amount of resolution in a microscope?

A. A low power magnification

B. A larger numerical aperture

C. A shorter focal length

D. B and C together would give the best resolution

E. All of the abovetogetherwould give the best resolution possible

In______________ the visual image is formed by light reflected or refracted by the specimen and is used to view a bright image of the object against a dark background

In ______________ the visual image is formed by converting differences in refractive index/cell density into detected variations in light intensity.

_____________ produces a magnification of 100 million times and can view atoms on a solid surface.

True or False: An advantage of phase contrast microscopy is that living cells do not have to be killed with stains in order to be visualized.

Which of the following is NOT true about SEM (scanning electron microscopy)

A. Uses electrons excited from the surface of a specimen to create detailed image

B. Can create 3-D images

C. Creates images using the back scatter of electrons or by capturing secondary electrons from the surface of the object to be visualized.

D. Images produced by SEM gain colors based on the fluorescent indexes of electrons

E. All of the above are true about SEM.

True or False: "Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea"

A mis-folded protein

Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called

The concept that human and animal diseases are caused by microorganisms is called the

Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?

Fracastoro

Koch

Pasteur

Lister

Who of the following was the first to observe and accurately describe microorganisms?

van Leeuwenhoek

Koch

Semmelweiss

Lister

Who of the following provided the evidence needed to discredit the concept of spontaneous generation?

Pasteur Koch Semmelweiss Lister

True or False: The relationship between specific bacteria and specific diseases was first demonstrated by Koch.

Whose work on spontaneous generation first demonstrated the existence of a very heat-resistant form of bacteria that are called endospores?

Schwann Redi Tyndall Pasteur

Antiseptic surgery was pioneered by

Pasteur Jenner Lister Kitasato

True or False: "Although developed over 100 years ago, Koch's postulates continue to be used successfully in all known human infectious diseases. "

True or False: Agar is used as a solidifying agent for microbiological media because it is not readily digested by most microorganisms.

True or False: All microorganisms can be grown on nutrient agar plates.

"If you are working in a laboratory and wish to create a pure culture of a virus, which of the following would best allow you to do this?"

A nutrient agar plate with LB media.

A tube of nutrient media broth.

A flask of living cells and nutrient media.

All of the above would allow you to do this.

The branch of microbiology that deals with diseases of humans and animals is called __________ microbiology.

The branch of microbiology that deals with the mechanisms by which the human body protects itself from disease-causing organisms is called __________.

__________ microbiologists monitor community food establishments and water supplies in order to control the spread of communicable diseases.

The branch of microbiology that studies the relationship between microorganisms and their habitats is called __________.

"__________ microbiology involves the use of microorganisms to make products such as antibiotics, vaccines, steroids, alcohols, vitamins, amino acids, and enzymes. "

"In an outbreak of the bacteria E. coli, who would be the most likely type of microbiologist to respond to the outbreak?"

An immunologist

An industrial microbiologist

A public health microbiologist

A molecular geneticis

. Which of the following external structures are found in archaea but not bacteria?

A. pili

B. flagella

C. hami

D. peptidoglycan

E. All of the above are found in both bacteria and archaea

Which of the following statements about archaeal plasma membranes is TRUE?

A. The plasma membrane is always a lipid bilayer that lacks integral membrane proteins.

B. The plasma membrane must be a lipid bilayer with embedded proteins.

C. The plasma membrane contains peptidoglycan.

D. The plasma membrane can be a lipid monolayer.

E. None of the above statements are true.

Diglycerol tetraether lipids __________.

A. are a characteristic feature of thermophilicbacteria

B. tend to make the membrane less rigid

C. are found in bothbacteria and archaeaD. form typical bilayer membranes in thermophilic eukaryotes

E. are found in thermophilicarchaea

The plasma membrane of eukaryotes contains all of the following except

A. sterols

B. phosphoglycerides

C. sphingolipids

D. peptidoglycan

E. cholesterol

How do eukaryotic cells move large particles out of a cell?

A. endocytosis

B. exocytosis

C. phagocytosis

D. pinocytosis

E. group translocation

__________ is used for the breakdown and recycling of cytoplasmic componentsin eukaryotic cells.

A. Receptor mediated endocytosis

B. Formation of clathrin coated pits

C. Macroautophagy

D. Caveolin-dependent endocytosis

E. Macropinocytosis

Which of the following is FALSE?

A. Histones are found in chromatin.

B. Histones are used to help coil DNA.

C. Histones are proteins.

D. Groups of histones and chromatin form nucleosomes.

E. Histones are found in prokaryotic and eukaryotic microorganisms.

Bacteria have a nucleolus.

A. True

B. False

Which of the following provides evidence in support of the endosymbiotic hypothesis?

A. Double membrane surrounding mitochondria.

B.Double membrane surrounding chloroplasts.

C. Observation of division by binary fission in mitochondria.

D. A and B only

E. A, B, and C

Mitochondria have their own extra nuclear DNA.

A. True

B. False

Which of the following statements is FALSE?

A. A virion is complete virus particle.

B. All virions have an envelope.

C. All virions have a nucleocapsid.

D. All virions have a nucleocapsid, but not all have an envelope.

E. Virion capsids are comprised of protomers.

Which of the following is NOT a form of viral genetic material?

A. ds DNA

B. ss DNA

C. ds RNA

D. ss RNA

E. All of the above are forms of viral genetic material.

what capsid shape is represented in the Ebola virus?

A virus that infects bacteria specifically is referred to as a

A. bacteriophage

B. bacterial virion

C. virube

D. V4

E. protease

Unlike bacteria, viruses do not have enzymes.

A. True

B. False

Why does influenza typically infect lung cells but not brain cells?

A. Due to the preference for macrophages over neuronal cells.

B. Due to host specificity.

C. Due to tissue tropism.

D. Due to host tropism.

E. Due to tissue deselectivity.

___ viruses typically lyse host cells upon release.

A. Enveloped

B. Non-enveloped

In the __________, phage DNA inserts into bacterial host genome where it is copied as a cell divides.

A. lytic cycle

B. acute cycle

C. virulent cycle

D. lysogenic cycle

E. archaeal cycle

Genes whose expression (or abnormal expression) causes cancer are called ___________.

A. carcinogens

B. progenies

C. cancerous genes

D. prototype genes

E. oncogenes

A plaque in virology refers to

A. a complete virus particle

B. anincomplete virus particle

C. a complete and infectious virus particle

D. an incomplete and infectious particle

E. a complete but non-infectious particle

The smallest amount of virus needed to cause infection in 50% of exposed host cells or organisms is called the__________.

A. lethal dose

B. infectious dose

C. innocuousdose

D. preferred dose

E. virulence dose

____are infectious nucleic acids that encode their own capsid proteins when helped by a helper virus.

A. Satellites

B. Prions

C. Viroids

D. Virions

E. Caspases

You diagnose a patient with Creutzfeldt-Jakob Disease. Will prescribing antibiotics help this patient with their condition?

A. Yes because it is a bacterialdisease.

B. No because it is a satellite disease.

C. No because it is a viral disease.

D. Yes because it is a viroid disease.

E. No because it is a prion disease

A circular shape in a microorganism is called

Diplo

Strepto

Staphylo

A rod-shaped microorganism

A curved rod

A coil-shaped microogranism

Spiral-shaped Microorganism

Helical shaped microorganism

These cells lack a true membrane-delimited nucleus

These cells have a membrane-enclosed nucleus, are more complex morphologically, and are usually larger than prokaryotic cells

Usually single-celled, Majority have cell wall with peptidoglycan

Most lack a membrane-bound nucleus

Ubiquitous and some live in extreme environments

Distinguished from Bacteria by unique rRNA gene sequences

No peptidoglycan in cell walls

Have unique membrane lipids

Some have unusual metabolic characteristics

Many live in extreme environments

algae, protozoa, slime molds, and water molds are examples of

Yeast and mold are examples of

smallest of all microbes

requires host cell to replicate

cause range of diseases, some cancers

infectious agents composed of RNA

Infectious proteins

first person to observe and describe microorganisms accurately

Belief that life comes from nonliving matter

The idea that living things only come from living things

discredited spontaneous generation when he showed that maggots on decaying meat came from fly eggs and did not arise from the meat its self

his experiment: First boiling, then sealing mutton broth in flasks, which resulted in a cloudy broth with microogranisms

This scientist first sealed, then boiled mutton broth in flasks, which resulted in no growth of microorganisms

These two set out to show there were living things in the air

Swan-neck flask’ experiments answered issues of critics about air and heat

The earliest established connection between microorganisms and disease were found in human diseases such as cholera and tuberculosis.

T/F?

demonstrated microorganisms carried out fermentations and developed the method of pastuerization, helping French wine industry

developed a system of surgery designed to prevent microorganisms from entering wounds as well as methods for treating instruments and surgical dressings

Established the relationship between Bacillus anthracis and anthrax

1.The suspected disease agent must be observed in every animal that has the disease, but not in healthy animals

2. The suspected disease agent must be extracted from a diseased animal and grown in a "pure" culture away from other types of cells, i.e., isolated from other possible disease agents

3. The suspected disease agent, which has been grown in the pure culture, must now be injected into healthy animals

4. The healthy animals must become diseased and the suspected disease agent must be observed in their bodies.

Are there any limitations to Koch’s postulates?

Q. How can limitations to Koch's postulates be overcome?

revolutionized all medicine by discovering the world's first antibiotic, or bacteria killer

___ is concerned with the impact of microorganisms on agriculture

____ studies metabolic pathways of microorganisms

____ study the nature of genetic information and how it regulates the development and function of cells and organisms

a measure of how greatly a substance slows the velocity of light

Distance between center of lens and focal point

Light rays are focused at a specific place called

the ability to distinguish closely spaced points as separate

Distance between the front surface of lens and surface of cover glass or specimen when it is in sharp focus

As you increase in magnification power, what happens to the working distance?

Shorter wavelength = ?

a measure of its ability to gather light and resolve fine specimen detail at a fixed object distance

Why is the highest power objective lens referred to as the “oil immersion” lens?

4 cocci in a square

sarcinae

network of long, multinucleate filaments

Which of the following is not a macromolecule?

1. Carbohydrates

2. Proteins

3. Lipids

4. Nucleic acids

5. Carbon Dioxide

These macromolecules are comprised of carbon, hydrogen, and oxygen in the ratio CH2O

These are complex macromolecules made from linking together amino acids by peptide bonds

hydrophobic molecules that include fats, steroids, and phospholipids, and play a critical role in cell membranes

the storage facilities for all the genetic material in life

a sugar + a phosphate + a nitrogenous base = ?

required in trace amounts

Mn, Zn, Co, Mo, Ni, and Cu are examples of

required in relatively large amounts

C, H, N, O, P, S, K, Ca, Mg, and Fe are examples of

transport mechanism used by Bacteria and Archaea

the movement of molecules from area of high concentration to low concentration

diffusion of small, hydrophobic molecules across the membrane

the transport of hydrophilic and charged molecules across the membrane

the movement of water across a membrane

When a solution is ______ the concentration of a solute is equal on both sides of the cell membrane

When a solution is _____ the concentration of a solute is greater on the inside of the cell membrane

When a solution is ___________ the concentration of a solute is greater outside of the cell membrane

_____ requires that a cell expend energy to move molecules across a membrane.

a membrane-bound vesicle fuses with the membrane and expels the large molecule

a vesicle forms around a large molecule and brings it into the cell

Rigid structure that lies just outside the cell plasma membrane

Two types based on standard Gram staining

stain purple; thick peptidoglycan

stain pink or red; thin peptidoglycan and outer membrane

Outermost layer in the cell envelope

short, thin, hairlike, proteinaceous appendages (up to 1,000/cell) that can mediate attachment to surfaces, motility, DNA uptake

longer, thicker, and less numerous (1-10/cell)–and are required for conjugation

one flagellum

flagella at each end of the cell

one flagellum at each end of cell

cluster of flagella at one or both ends

flagella spread over entire surface of cell

Movement toward chemical attractant or away from chemical repellent

In flagella, counterclockwise (CCW) rotation causes forward motion and is called

In flagella, clockwise rotation (CW) disrupts run causing cell to stop is called

Complex, dormant structure formed by some bacteria and is resistant to numerous environmental conditions

Why are bacteria haploid?

Binary fission and budding are examples of what type of reproduction?

True or False: There is no mitotic phase for bacteria.

True or False: All bacterial chromosomes are circular

The site at which replication begins on a bacterial chromosome

The site at which replication is terminated, located opposite of the origin on a bacterial chromosome

A group of proteins needed for DNA synthesis

formation of cross walls between daughter cells

These microbes grow optimally in the presence of NaCl or other salts at a concentration above about 0.2M

These microbes require salt concentrations of 2M and 6.2M

What is the difference between a halotolerant microbe and a halophile?

A chemical compound that releases H+to a solution is a(n)___

A compound that accepts H+and removes them from solution is a(n)__

These microbes grow optimally between pH 0 and pH 5.5

These microbes grow optimally between pH 5.5 and pH 7

These microbes grow optimally between pH 8.5 and pH 11.5

These microbes grow between 0 degrees C to 20 degrees C

These microbes grow between 0 degrees C to 35 degrees C

These microbes grow between 20degrees C to 45 degrees C

These microbes grow between 55 degrees C to 85 degrees C

These microbes grow between 85 degrees C to 113 degrees C

These microbes grow in presence of atmospheric oxygen (O2) which is 20% O2

These microbes require O₂

These microbes grow in the absence of O₂

These microbes usually killed in presence of O₂

These microbes do not require O₂ but grow better in its presence

These microbes require 2–10% O₂

____ grow with or without O₂

important antioxidant defense in nearly all living cells exposed to oxygen; out-competes damaging reactions of superoxide

Ubiquitous in nature in water, these are complex, slime enclosed communities of microbes

This media favors the growth of some microorganisms and inhibit growth of others

This type of media can distinguish between different groups of microorganisms based on their biological characteristics

True or False: Media can be selective or differential, but not both.

Which is not a phase in the growth curve?

Lag phase

Communal phase

Exponential(log) phase

Stationary phase

Death phase

At 8:00 a.m., a closed flask of sterile broth is inoculated with 1,000 cells. The lag phase lasts 2.5 hours. At 2:00 p.m. the log phase culture has a population of 6 million cells. The mean generation time is approximately_______?

What is used to accomplish microbial metabolism?

Chemical work, Transport work, and Mechanical work all make up

In metabolism, the synthesis of complex molecules is __

In metabolism, take up of nutrients, elimination of wastes, and maintenance of ion balances is ___

In metabolism, cell motility and movement of structures within cells is ____

the breakdown of organic molecules

The synthesis of organic molecules

One is electron donating(oxidizing reaction)

One is electron accepting reaction (reducing reaction)

NAD, NADP, FAD, FMN, and CoQ are

____ speed up the rate at which a reaction proceeds toward its final equilibrium

protein component of an enzyme

non-protein component of an enzyme

firmly attached non-protein component of an enzyme

loosely attached non-protein component of an enzyme

apoenzyme+ cofactor =

Why would an enzyme denature at high temperatures?

directly competes with binding of substrate to active site

binds enzyme at site other than active site and changes enzyme’s shape so that it becomes less active

_____ pathways are enzyme catalyzed reactions whereby the product of one reaction serves as the substrate for the next

____ pathways function both as catabolic and anabolic pathways

What are these three pathways used for?

Embden-Meyerhof pathway

pentose phosphate pathway

Entner-Duodoroffpathway

Also known as glycolysis, this is the most common pathway for glucose degradation to pyruvate in stage two of aerobic respiration and can function with or without O₂

True or False: The Embden-Meyerhof Pathway has three phases.

Used by soil bacteria and a few gram-negative bacteria, this pathway replaces the first phase of the Embden-Meyerhof pathway and yields 1 ATP, 1 NADPH, and 1 NADH per glucose molecule

Also called the hexose monophosphate pathway, this pathway can operate at same time as glycolytic pathway or Entner-Duodoroff pathway

Also called citric acid cycle and Kreb’scycle

•Common in aerobic bacteria, free-living protozoa, most algae, and fungi

•Major role is as a source of carbon skeletons for use in biosynthesis

•Summary: for each acetyl-CoA molecule oxidized, generate 2 molecules of CO2, 3 molecules of NADH, one FADH2, and one GTP

True or False: All electron transport chains are found in the mitochondrial inner membrane.

The most widely accepted hypothesis to explain oxidative phosphorylation

The theoretical maximum total yield of ATP during aerobic respiration is

Net gain of 146 ATP under aerobic conditions

____ hydrolyzes protein to amino acids

___ is the removal of amino group from amino acid

_____ bacteria oxidize ammonia to nitrate

A process of photosynthesis where light energy is trapped and converted to chemical energy

A process of photosynthesis where energy produced in the light reactions is used to reduce CO2 and synthesize cell constituents

_________ is the total of all chemical reactions occurring in the cell.

Cells carry out three major types of work; which of the following involves nutrient uptake and waste elimination?

Chemical work. Transport work. Mechanical work. None of these.

Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells?

Chemical work. Transport work. Mechanical work. None of these.

The change in __________ is the amount of energy in a system that is available to do work.

The __________ is the electron acceptor in a redox reaction.

The standard reduction potential of a redox reaction is a measure of the tendency of the __________ to __________ electrons.Ê

True or False: The equilibrium constant for a redox reaction is called the standard reduction potential.

Which of the following is used as an electron carrier by living organisms?

NAD+

NADP+

ubiquinone

all of the choices

True or False: The electron transport chain is based on the principle that redox couples with more positive reduction potentials will donate electrons to couples with more negative potentials.Ê

Which of the following is not true about enzymes?

Enzymes are catalysts that speed up reactions.

Enzymes are proteins that can be denatured by changes in pH or temperature.

Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates.

All of the choices are true about enzymes

The most specific term usually used to describe a substance in a biological system that increases the rate of a reaction without being permanently changed by the reaction is a(n)

Enzymes catalyze a reaction byÊ

"The synthesis of ATP from ADP and Pi, when coupled with an exergonic chemical reaction is called __________ phosphorylation. Ê"

The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhoff pathway in prokaryotes is Ê

The net gain of ATP per molecule of glucose metabolized to pyruvate using Entner-Doudoroff pathway is Ê

The pentose phosphate pathway produces Ê

CO2.

NADPH.

glyceraldehyde

3-phosphate.

all of the choices.

The most common pathway for conversion of glucose to pyruvate is Ê

The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO2 and Ê

The TCA cycle generates all of the following from each acetyl-CoA molecule oxidized except Ê

three NADH molecules.

two CO2 molecules.

one FADH2 molecule.

two ATP or GTPÊmolecules.

The major function(s) of the TCA cycle is(are) Ê

The most commonly accepted hypothesis for the production of ATP that results from electron transport system is called the __________ hypothesis. Ê

The electron transport systems in eukaryotes and prokaryotes use the same electron carriers. Ê

"In higher eukaryotes, most aerobically generated ATP is produced by Ê"

"In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.Ê"

The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O2 is called the Ê

Fermentation does not involve the use of pyruvate and/or other organic molecules as electron acceptors.Ê

Which of the following can be used as electron acceptors during anaerobic respiration?Ê

nitrate sulfate carbon dioxide

Fatty acids are metabolized by the __________ pathway. Ê

"During breakdown of fatty acids, carbons are removed __________ at a time with each turn of the cycle, and two carbon units are released Êas __________. Ê"

Amino acids are processed first by the removal of the amino group through Ê

Which of the following may be used as sources of energy by chemolithotrophs?Ê

Hydrogen gas. Reduced nitrogen compounds. Reduced sulfur compounds.

Photosynthetic electron transport in cyanobacteria takes place Ê

Most bacterial and archaeal cells divide by

"The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell."

The actin-like protein that seems to be involved in determining cell shape is

"During cytokinesis, a critical step in septation is the assembly of the "

Quorum sensing

is a phenomenon in which bacteria monitor their own population density.

depends on the sensing of signal protein molecules.

plays an important role in formation of biofilms by Pseudomonas aeruginosa.

Which of the following can be used to isolate pure cultures of bacteria from mixtures?

spread plates streak plates pour plates

Media containing some ingredients of unknown chemical composition are called __________ media.

"Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes); nonhalophiles will not grow. Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter and a halophilic mannitol nonfermenter. In this case, the medium is acting as (a) __________ medium/"

"Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters release acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol nonfermenter and a nonhalophilic mannitol nonfermenter. Here the medium acts as a __________ medium. "

Media in which all components and their concentration are known are called __________ media.

The total number of viable microorganisms remains constant in stationary phase because

Cells may enter stationary phase because of

the depletion of an essential nutrient.

a lack of available oxygen.

the accumulation of toxic waste products.

Which of these methods can be used to determine the number of viable microorganisms in a sample?

Light scattering in a spectrophotometer.

Measuring total cell mass.

Measuring colony forming units per ml.

Counting a known volume of cells in a hemocytometer.

Microorganisms are most nearly uniform in terms of chemical and physiological properties during __________ phase.

Which of the following is a reason for the occurrence of a lag phase in a bacterial growth curve?

"The cells may be old and depleted of ATP, essential cofactors, and ribosomes that must be synthesized before growth can begin."

The medium may be different from the previous growth medium so that the cells must synthesize new enzymes to use different nutrients.

The organisms may have been injured and require time to recover.

All of these are potential reasons.

"If all cell components are synthesized at constant rates relative to one another, the culture is said to be in __________ growth; however, if the rates of synthesis of some components change relative to the rates of synthesis of other components, the culture is said to be in __________ growth. "

"Given a log phase bacterial culture with 1 x 10^6 cells per ml and a generation time of 30 minutes, how long does it take the culture to reach a density of 6.4x 10^7 cells per ml? "

"At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has population of 65 million cells. The approximate number of generations that has occurred is"

"At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has a population of 65 million cells. The mean generation time is approximately"

The Archaea generally lack which of the following that are normally found in gram-negative bacteria?

Outer membrane.

A complex peptidoglycan network.

Lipopolysaccharide.

A feature unique to some archaeal plasma membranes is that they may

Because archaeons lack peptidoglycan in their cell walls

Archaeal membranes contain which of the following lipids?

phospholipids sulfolipids glycolipids

Diglycerol tetraether lipids

"Which of the following organelles is involved in the modification, packaging, and secretion of materials? "

Receptor mediated endocytosis

The nucleolus plays a major role in synthesis of

Which is not true of viruses?

They can exist in an intracellular or extracellular phase.

They infect animal and plant cells only.

They replicate only inside host cells. They are acellular.

A complete virus particle is called a

The nucleic acids carried by viruses usually consist of

Which of the following is not true of viruses?

Viruses are acellular.

Viruses consist of one or more molecules of DNA or RNA enclosed in a coat of protein and sometimes in other more complex layers.

Viruses can exist in two phases: intracellular and extracellular.

Viruses replicate by binary fission.

"In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the "

Viral capsid protein subunits are called

Glycoprotein spikes protruding from the outer surface of viral envelopes function as

The function of the viral protein coat is to

Most enveloped viruses use the host __________ membrane as their envelope source.

Nonenveloped viruses most often gain access to eukaryotic host cells by

Animal viruses have been cultivated in

suitable host animals.

embryonated eggs.

tissue cultures (monolayers of animal cells).

A ________ assay is most useful for determining the viability of a viral preparation?

Viroids are of economic significance because they cause disease in

Which of the following diseases is (are) caused by prions?

Scrapie. Mad cow disease. Kuru and Creutzfeldt-Jakob Disease.

Which of the following individuals or groups of individuals demonstrated that the transforming principle was DNA?

" Avery, MacLeod, and McCarty"

Griffith

Hershey and Chase

Watson and Crick

The principle of transformation was first demonstrated by which of the following individuals or groups of individuals?

" Avery, MacLeod, and McCarty"

Griffith

Hershey and Chase

Watson and Crick

"Hershey and Chase demonstrated that when the bacteriophage T2 infected its host cell, the __________ is injected into the host but the __________ remained outside. "

The genetic information in DNA is divided into units called

Which of the following is true about the structure of DNA?

Purine and pyrimidine bases are attached to the 1'-carbon of the deoxyribose sugars.

Purine and pyrimidine bases are joined by phosphodiester bonds. "

Adjacent bases are stacked on top of each other, one base pair every 0.34 nm."

all of the above are true.

Which of the following is not a pyrimidine?

adenine cytosine thymine uracil

"The two strands of a DNA molecule are __________; that is, they are oriented in opposite directions. "

"When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called __________ replication. "

The chromosomes of most bacteria are comprised of

During replication the 2 strands of the DNA molecule are unwound from one another by enzymes called

"The coding sequence in the DNA of __________ is normally continuous; that is, it is not interrupted by noncoding sequences. "

The process by which the base sequence of all or a portion of a DNA molecule is used to direct the synthesis of an RNA molecule is called

The region at which the RNA polymerase binds is the __________ region.

"The transcribed, but not translated, sequence that is immediately upstream of the region that encodes the functional product is called the __________ region. "

The unexpressed regions of split genes are called

The strand of DNA for a particular gene that is copied by the RNA polymerase to form mRNA is called the __________ stran

Messenger RNA molecules that direct the synthesis of more than one polypeptide are said to be __________.

A consensus sequence in the untranslated leader sequence of a prokaryotic mRNA which serves as a ribosome binding site is called the __________ sequence.

The process by which the base sequence of an RNA molecule is used to direct the synthesis of a protein is called

________ molecules deliver amino acids to ribosomes during translation.

Which of the following is not a termination codon?

The portion of the tRNA molecule that binds to the codon on the mRNA is called the

What is the minimum number of aminoacyl-tRNA synthetase enzymes needed to attach amino acids to all the various tRNA molecules?

In __________ ribosomes can attach to the mRNA and begin translation even though transcription has not been complete

The energy needed for protein synthesis is provided by the hydrolysis of

___________ in proteins includes alpha-helixes and beta-pleated sheets.

What are used to regulate protein folding to minimize the risk of protein mis-folding?

A gram negative bacterium wishes to secrete a previously-folded virulence factor. Which of the following secretion systems would be used to accomplish this?