Superantigens produce intense immune responses by stimulating lymphocytes to produce ___.

Superantigens produce intense immune responses by stimulating lymphocytes to produce ___. A. endotoxins B. exotoxins C. cytokines D. leukocidins E....

Competent cells are cells that _____.

Competent cells are cells that _____. A. can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination B....

Hfr cells arise when _____.

Hfr cells arise when _____. A. they have multiple F plasmids B. a cell's F plasmid has been incorporated into the bacterial chromosome C. conjugation...

A gene is best defined as ______.

A gene is best defined as ______. A. a segment of DNA B. three nucleotides that code for an amino acid C. a segment of DNA that codes for a functional...

tRNA molecules serve as a link between ______.

tRNA molecules serve as a link between ______. A. DNA and mRNA B. codons and anticodons C. codons and amino acids D. mRNA and rRNA Answer: C....

Two daughter cells are most likely to inherit which one of the following from the parent cell?

Two daughter cells are most likely to inherit which one of the following from the parent cell? A. A change in a nucleotide in mRNA. B. A change in...

Which of these is a mutation?

Which of these is a mutation? A. A change in the gene that codes for the Lactase enzyme. B. An error in translation that produces a Lactase enzyme...

A bacterium has received new DNA that does not give it a new ability. Which of the following statements is true?

A bacterium has received new DNA that does not give it a new ability. Which of the following statements is true? A. There is a change in both the...

Which of the following would most likely result in a frameshift mutation?

Which of the following would most likely result in a frameshift mutation? A. An adenine is inserted into the DNA sequence of an organism B. A thymine...

What is the function of the Parental DNA in replication?

What is the function of the Parental DNA in replication? A. It is passed into the offspring of the parent. B. It allows for the DNA to be circular. C....

Which of these is characteristic of nonionizing radiation with respect to the DNA damage?

Which of these is characteristic of nonionizing radiation with respect to the DNA damage? A. Cause structural damage B. Causes mismatched base pairing...

Which type of plasmid is most likely to carry the gene for an enzyme that can metabolize the sugar arabinose?

Which type of plasmid is most likely to carry the gene for an enzyme that can metabolize the sugar arabinose? A. F plasmid B. R plasmid C. A dissimulation...

Which of these types of mutations is potentially the least damaging?

Which of these types of mutations is potentially the least damaging? A. Silent mutations B. Missense mutations C.Nonsense mutations Answer: A....

DNA replication is _____.

DNA replication is _____. A. Semi conservative B. Conservative C. Dispersive D. Conservative on the lagging strand Answer: A. Semi conserv...

Cells able to accept naked DNA from the surrounding area are said to be ____.

Cells able to accept naked DNA from the surrounding area are said to be ____. A. Transduction ready B. Capable C. Competent D. Transformable Answer: C....

Which of the following is not a method of horizontal gene transfer?

Which of the following is not a method of horizontal gene transfer? A. Binary Fission B. Conjugation C. Transfer of DNA via a bacteriophage infection D....

Which of the following pairs is mismatched?

Which of the following pairs is mismatched? A. DNA polymerase-makes a molecule of DNA from a DNA template B. RNA polymerase-makes a molecule of DNA...

During which process do most mutations occur?

During which process do most mutations occur? A. DNA replication B. Transcription C. Translation D. Transduction Answer: A. DNA replicatio...

An enzyme that covalently bonds nucleotides together is _____.

An enzyme that covalently bonds nucleotides together is _____. A. DNA polymerase B. RNA polymerase C. The ribosome D. Both DNA and RNA polymerase Answer: D....

When discussing a microbe's ability to resist an antibiotic, you are talking about the organism's ______.

When discussing a microbe's ability to resist an antibiotic, you are talking about the organism's ______. A. Genotype B. Phenotype Answer: B....

A sequence of DNA nucleotides which provides genetic information for a functional product is a _____.

A sequence of DNA nucleotides which provides genetic information for a functional product is a _____. A. Chromosome B. Plasmid C. Gene D. Base pair Answer: C....

What must occur for bacterial conjugation to take place?

What must occur for bacterial conjugation to take place? A. Each cell must contain a plasmid. B. The cells must come into contact with each other. C....

Nucleoside analogs can cause mutations by _____.

Nucleoside analogs can cause mutations by _____. A. Interfering with normal pairing of bases B. Causing structural damage to DNA C. Forming covalent...

Which enzyme is responsible for unzipping the double-stranded DNA?

Which enzyme is responsible for unzipping the double-stranded DNA? A. DNA polymerase B. DNA helicase C. DNA ligase D. DNA zippase E. DNA unzippase Answer: B....

The drug chloramphenicol binds to the 50S ribosomal subunit of bacteria. From this information you can conclude that chloramphenicol _____.

The drug chloramphenicol binds to the 50S ribosomal subunit of bacteria. From this information you can conclude that chloramphenicol _____. A. Prevents...

An enzyme that copies DNA to make a molecule of RNA is ____.

An enzyme that copies DNA to make a molecule of RNA is ____. A. RNA polymerase B. DNA ligase C. Transposes D. DNA polymerase Answer: A. RNA...

A cell that cannot make tRNA _____.

A cell that cannot make tRNA _____. A. can make proteins if amino acids are provided in the growth medium. B. can make proteins if mRNA is provided...

Which of the following statements regarding genomes is true?

Which of the following statements regarding genomes is true? A. Plasmids are not considered part of the genome because they are not a part of the...

DNA replication is the synthesis of DNA from a _____ template.

DNA replication is the synthesis of DNA from a _____ template. A. DNA B. RNA C. protein Answer: A. DN...

Which of the following is not true of a bacterium that is R+?

Which of the following is not true of a bacterium that is R+? A. R+ refers to the possession of a plasmid. B. R+ can be transferred to a recipient...

What are the products of semiconservative replication for a double-stranded DNA molecule?

What are the products of semiconservative replication for a double-stranded DNA molecule? A. Two double-stranded DNA molecules, one consisting of...

Which of the following properties are exclusive (unique) to tRNA?

Which of the following properties are exclusive (unique) to tRNA? A. Combines with specific proteins to form ribosomes. B. carries information from...

Which of the following properties are exclusive (unique) to mRNA?

Which of the following properties are exclusive (unique) to mRNA? A. Combines with specific proteins to form ribosomes. B. carries information from...

____ refers to the specific characteristics displayed by an organism.

____ refers to the specific characteristics displayed by an organism. A. Genotype B. Mutation C. Phenotype D. Genes Answer: C. Phenotyp...

Which of the following properties are exclusive (unique) to rRNA?

Which of the following properties are exclusive (unique) to rRNA? A. Combines with specific proteins to form ribosomes. B. Carries information from...

The genetic information needed for a F+ cell to participate in conjugation can be found in the DNA of a cell's ____.

The genetic information needed for a F+ cell to participate in conjugation can be found in the DNA of a cell's ____. A. chromosome B. F factor C....

A bacterium has received new DNA that allows it to produce a toxin. Which of the following statements is true?

A bacterium has received new DNA that allows it to produce a toxin. Which of the following statements is true? A. There is a change in both the genotype...

Bacteria which show a variety of shapes within a single species are said to be ______.

Bacteria which show a variety of shapes within a single species are said to be ______. A. Pleomorphic B. Axenic C. Monomorphic D. Manymorphic Answer: A....

If you isolate LPS from the cell wall of an unknown microbe, you know that _________.

If you isolate LPS from the cell wall of an unknown microbe, you know that _________. A. You have isolated a virus. B. You have isolated an archaea. C....

Why is no energy required in passive transport?

Why is no energy required in passive transport? A. The membrane physically moves the molecules. B. The concentration gradient drives the movement. C....

How would a cell without flagella be described?

How would a cell without flagella be described? A. Monotrichous B. Nontrichous C. Pseudotrichous D. Atrichous E. Peritrichous Answer: D. A...

Fimbriae and pili differ in that pili ______.

Fimbriae and pili differ in that pili ______. A. Are used to transfer DNA. B. Are composed of pilin. C. Are used for asexual reproduction. D. Are...

Which organelle is used to produce sugars from carbon dioxide and sunlight?

Which organelle is used to produce sugars from carbon dioxide and sunlight? A. Mitochondria B. Chloroplasts C. Lysosomes D. Endoplasmic reticulum E....

Which structure can protect bacteria from being phagocytized?

Which structure can protect bacteria from being phagocytized? A. Slime layer B. Fimbriae C. Capsule D. Cell membrane E. Cell wall Answer: C....

Cells placed in a hypotonic solution tend to lose water due to osmotic pressure.

Cells placed in a hypotonic solution tend to lose water due to osmotic pressure. A. True B. False Answer: B. Fals...

Which of these organelles are found in algae, but not fungi?

Which of these organelles are found in algae, but not fungi? A. Mitochondria B. Chloroplasts C. Ribosomes D. ER E. Lysosomes Answer: B. Ch...

Even though narrow spectrum antibiotics are only effective against a few species, they are preferred because ______.

Even though narrow spectrum antibiotics are only effective against a few species, they are preferred because ______. A. They can kill microbes faster. B....

Which of the following cell structures has a role in the initiation of disease?

Which of the following cell structures has a role in the initiation of disease? A. Cell membrane B. Fimbriae C. Flagella D. Gram-positive cell wall E....

If a eukaryotic cell lost its peroxisomes, it would _____.

If a eukaryotic cell lost its peroxisomes, it would _____. A. Lose the ability to generate cell energy. B. Lose the ability to digest solid waste. C....

If you isolate teichoic acid from the cell wall of an unknown microbe, you know that _________.

If you isolate teichoic acid from the cell wall of an unknown microbe, you know that _________. A. You have isolated a eukaryotic cell. B. You have...

Which of the following molecules can freely cross the plasma membrane?

Which of the following molecules can freely cross the plasma membrane? A. H2 B. 1O2- C. A nucleotide D. Sucrose Answer: B. 1O2...

What is the function of the ER?

What is the function of the ER? A. Synthesize molecules B. Breakdown toxins C. Transport molecules D. Stores excess energy reserves. E. Generate ATP Answer: A....

In a hypotonic solution, a Gram-positive bacterial cell will typically ______.

In a hypotonic solution, a Gram-positive bacterial cell will typically ______. A. Shrink B. Burst C. Stay the same D. Plasmolyze E. Osmolyze Answer: E....

By which of the following mechanisms can a cell transport a substance from a lower concentration to a higher concentration?

By which of the following mechanisms can a cell transport a substance from a lower concentration to a higher concentration? A. Simple diffusion B....

Some microbes can cause secondary infections after being killed by antibiotics due to the release of an LPS endotoxin. Which of these microbes could cause such an infection?

Some microbes can cause secondary infections after being killed by antibiotics due to the release of an LPS endotoxin. Which of these microbes could...

Which of the following statements is true?

Which of the following statements is true? A. Endospores are for reproduction. B. Endospores allow a cell to survive environmental changes. C. A cell...

Positive phototaxis describes ___.

Positive phototaxis describes ___. A. Movement towards a light source. B. Movement away from a light source. C. Rotation nearby a light source. D....

Which of the following molecules would be blocked by a cell membrane?

Which of the following molecules would be blocked by a cell membrane? A. Carbon dioxide B. Ions C. Water D. Oxygen Answer: B. Ion...

Antibiotics that target the cell wall are an effective treatment against pathogenic bacteria.

Antibiotics that target the cell wall are an effective treatment against pathogenic bacteria. A. True B. False Answer: A. Tru...

Which of the following is not a characteristic of the plasma membrane?

Which of the following is not a characteristic of the plasma membrane? A. Composed of a phospholipid bilayer. B. Maintains cell shape C. Selectively...

What is responsible for making proteins?

What is responsible for making proteins? A. DNA B. Rough ER C. ATP D. mRNA E. Ribosomes Answer: E. Ribosome...

Oxygen crosses a plasma membrane ___.

Oxygen crosses a plasma membrane ___. A. By osmosis B. Through simple diffusion C. With the help of a nonspecific transporter. D. Through facilitated...

Which of these is not considered a part of bacterial cytoplasm?

Which of these is not considered a part of bacterial cytoplasm? A. Nucleoid B. LPS C. Endospore D. An inclusion Answer: A. Nucleoi...

What will happen if a bacterial cell is placed in 10% NaCI (hypertonic)?

What will happen if a bacterial cell is placed in 10% NaCI (hypertonic)? A. The cell will undergo plasmolysis. B. The cell will undergo osmotic lysis. C....

Each of following statements concerning the gram-positive cell wall is true except ___.

Each of following statements concerning the gram-positive cell wall is true except ___. A. It maintain the shape of the cell. B. It is sensitive to...

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of ___.

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of ___. A. Lysis B. Inhibition of molecular transport. C....

Which of the following statements is correct about simple diffusion?

Which of the following statements is correct about simple diffusion? A. It requires an expenditure of energy by the cell. B. Is is a passive process...

Which of the following organelles are responsible for generating ATP?

Which of the following organelles are responsible for generating ATP? A. Ribosomes B. Golgi complex C. Lysosome D. Mitochondria E. Chloroplasts Answer: D....

What of these processes requires energy?

What of these processes requires energy? A. Simple diffusion B. Facilitated diffusin C. Active transport Answer: C. Active transpor...

Which bacterial genus does not have a cell wall?

Which bacterial genus does not have a cell wall? A. Mycobacterium B. Streptococcus C. Mycoplasma D. Bacillus E. Staphylococcus Answer: C. ...

The shape of a bacterial cell is determined primarily by the ___.

The shape of a bacterial cell is determined primarily by the ___. A. Cell membrane B. Cell wall C. Capsule D. Slime layer E. Flagella Answer: B....

What would likely occur to a halophile (salt-loving bacteria) that's placed into high salt environment?

What would likely occur to a halophile (salt-loving bacteria) that's placed into high salt environment? A. The cell would plasmolyse. B. The cell...

Small hydrophobic molecules would likely enter a cell ___.

Small hydrophobic molecules would likely enter a cell ___. A. By active transport directly across the membrane. B.Through integral transport proteins. C....

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?  A. They are positive charged. B. They...

Penicillins show great selective toxicity because ____.

Penicillins show great selective toxicity because ____. A. They are very simple to create. B. They are enzymes. C. Peptidoglycan is not found in human...

What is the similarity between facilitated diffusion and active transport?

What is the similarity between facilitated diffusion and active transport? A. Both require energy. B. Both require transport proteins. C. Both move...

Where are phospholipids most likely found in a eukaryotic cell?

Where are phospholipids most likely found in a eukaryotic cell?  A. Ribosomes B. Around organelles C. Flagella D. Plasma membrane E. Both the...

In a Gram-negative, the peptidoglycan layer exists ____.

In a Gram-negative, the peptidoglycan layer exists ____. A. In the periplasm. B. Underneath the plasma membrane, inside the cell. C. On top of the...

Which of the following is not a common bacterial shape?

Which of the following is not a common bacterial shape?  A. Spirochete B. Coccus C. Square D. Bacillus Answer: C. Squar...

A sodium ion can pass through the plasma membrane because the positive charge allows it to bind to the negative phospholipid.

A sodium ion can pass through the plasma membrane because the positive charge allows it to bind to the negative phospholipid. A. True B. False Answer: B....

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?  A. Standard plate count B. Glucose...

Which of these quantification methods would be most accurate when quantifying a filamentous mold culture?

Which of these quantification methods would be most accurate when quantifying a filamentous mold culture? A. Plate count B. Filtration C. Turbidity D....

Which nutritional requirement is iron (Fe2+) considered to be a part of?

Which nutritional requirement is iron (Fe2+) considered to be a part of? A. The major nutritional elements B. Trace elements C. Organic growth factors D....

During which phases of the bacterial growth curve are there no changes in the number of living cells?

During which phases of the bacterial growth curve are there no changes in the number of living cells?  A. Stationary and death phase B. Lag phase...

At which stage of bacterial growth is cell division the most rapid?

At which stage of bacterial growth is cell division the most rapid?  A. Lag B. Log C. Stationary D. Death Answer: B. Lo...

Cells that live in high salt environments are called ________.

Cells that live in high salt environments are called ________.  A. plasmophiles B. saltophiles C. tonophiles D. halophiles Answer: D....

Which of these does not contain nitrogen?

Which of these does not contain nitrogen? A. Carbohydrates B. Proteins C. DNA D. RNA Answer: A. Carbohydrate...

Which of these microbes would not contain superoxide dismutase?

Which of these microbes would not contain superoxide dismutase? A. Obligate aerobe B. Facultative aerobe C. Obligate anaerobe D. Aerotolerant anaerobe Answer: C....

All of the following are true about agar except ______.

All of the following are true about agar except ______. A. it is a source of nutrients in culture media B. it is a polysaccharide C. it solidifies...

The large intestine is an environment that lacks any oxygen. Which of the following types of organisms would most likely be found there?

The large intestine is an environment that lacks any oxygen. Which of the following types of organisms would most likely be found there?  A....

What toxic oxygen form of oxygen does the enzyme catalase detoxify?

What toxic oxygen form of oxygen does the enzyme catalase detoxify?  A. Superoxide free radical B. Singlet oxygen C. Peroxide anion D. Hydroxyl...

While ____ is able to detoxify a reactive oxygen species, it also produces one, hydrogen peroxide.

While ____ is able to detoxify a reactive oxygen species, it also produces one, hydrogen peroxide. A. Superoxide dismutase B. Catalase C. Peroxidase D....

At which stage of bacterial growth does cell division NOT occur?

At which stage of bacterial growth does cell division NOT occur?  A. Lag B. Log C. Stationary D. Death Answer: A. La...

Lactic acid bacteria, the bacteria involved in making kimchi and yogurt, are strict fermenters. What can you say about their requirements for oxygen?

Lactic acid bacteria, the bacteria involved in making kimchi and yogurt, are strict fermenters. What can you say about their requirements for oxygen?  A....

Penicillin functions by inhibiting the formation of new cell walls. At what stage of bacterial growth is penicillin most effective? Hint - when do you think cells are making new cell walls?

Penicillin functions by inhibiting the formation of new cell walls. At what stage of bacterial growth is penicillin most effective? Hint - when do you...

You want to quantify a culture of motile bacteria. Which method of quantifying would you use if you needed the most accurate information as soon as possible?

You want to quantify a culture of motile bacteria. Which method of quantifying would you use if you needed the most accurate information as soon as...

Salts and sugars work to preserve foods by creating a ____.

Salts and sugars work to preserve foods by creating a ____.  A. lower osmotic pressure B. hypotonic environment C. lower pH D. hypertonic environment Answer: D....

Which of the following is the best definition of generation time?

Which of the following is the best definition of generation time?  A. The length of time needed for lag phase B. The length of time needed for...

What is the difference between peroxidase and catalase?

What is the difference between peroxidase and catalase?  A. Peroxidase detoxifies hydrogen peroxide, catalase detoxifies hydroxyl radicals. B....

Most human pathogens are _________.

Most human pathogens are _________. A. psychrophiles B. mesophiles C. thermophiles D. psychrotrophs Answer: B. Mesophile...

Which method of quantifying bacterial numbers would be most effective for measuring the numbers of bacteria in drinking water, when you expect the numbers to be relatively low?

Which method of quantifying bacterial numbers would be most effective for measuring the numbers of bacteria in drinking water, when you expect the numbers...

Which pH is considered alkaline?

Which pH is considered alkaline? A. 4 B. 2 C. 7 D. 10 Answer: D. 1...

The term aerotolerant anaerobe refers to an organism that ______.

The term aerotolerant anaerobe refers to an organism that ______. A. does not use oxygen but tolerates it B. is killed by oxygen C. uses oxygen or...

In which phase is the rate of cell death equal to the rate of cell growth?

In which phase is the rate of cell death equal to the rate of cell growth?  A. Log phase B. Death phase C. Log and death phase D. Stationary...

Luria Broth (LB) is a medium containing Tryptone, yeast extract, and sodium chloride.

Luria Broth (LB) is a medium containing Tryptone, yeast extract, and sodium chloride.  A. LB is a chemically defined medium. B. LB is a complex...

Coffee has a pH of approximately 5. What type of microbe can grow in your coffee?

Coffee has a pH of approximately 5. What type of microbe can grow in your coffee?  A. acidophile B. alkalinophile C. halophile D. extreme halophile Answer: A....

Why might cells begin to die at a faster rate than new cells are made?

Why might cells begin to die at a faster rate than new cells are made? A. Original cells get too old. B. Increase in cellular waste products. C. Lack...

Most bacteria reproduce by ______.

Most bacteria reproduce by ______. A. sexual reproduction B. binary fission C. budding D. mitosis Answer: B. binary fissio...

Which of these microbes is most problematic to human health?

Which of these microbes is most problematic to human health?  A. Psychrophiles B. Psychrotrophs C. Mesophiles D. Thermophiles E. Hyperthermophiles Answer: C....

Bacterial growth is defined as _____.

Bacterial growth is defined as _____. A. increase in bacterial cell population B. increase in cell length C. increase in cellular proteins D. increase...

Aerobic bacteria that have developed (or retain) the ability to continue growing in the absence of oxygen are called _____.

Aerobic bacteria that have developed (or retain) the ability to continue growing in the absence of oxygen are called _____.  A. obligate anaerobes B....

Which of the following organisms most likely does not have catalase?

Which of the following organisms most likely does not have catalase? A. An aerotolerant anaerobe. B. An obligate anaerobe. C. A facultative anaerobe. D....

Which of the following is an advantage of the standard plate count?

Which of the following is an advantage of the standard plate count?  A. Can readily count cells that form aggregates. B. Determines the number...

Protein synthesis during lag phase is not occurring because cells are not actively dividing.

Protein synthesis during lag phase is not occurring because cells are not actively dividing. A. True B. False Answer: B. False...

Thirty-six colonies grew on nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?

Thirty-six colonies grew on nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample? A....

Which of the following is an advantage of the direct microscopic count?

Which of the following is an advantage of the direct microscopic count? A. Can readily count organisms that are motile. B. Can easily distinguish...

Which of these organisms would not be able to grow in water that has oxygen pumped into it (aerated)?

Which of these organisms would not be able to grow in water that has oxygen pumped into it (aerated)? A. Obligate aerobe B. Facultative aerobe C....

Which of these microbes is most likely to grow at room temperature (25 C)?

Which of these microbes is most likely to grow at room temperature (25 C)? A. Psychrophile B. Psychrotroph C. Thermophile D. Hyperthermophile Answer: B....

Shoyu is highly salty (often higher than 28%). What type of microbe can grow in shoyu?

Shoyu is highly salty (often higher than 28%). What type of microbe can grow in shoyu? A. acidophile B. alkalinophile C. halophile D. extreme thermophile Answer: C....

Organisms that grow near deep‐sea volcanic vents are likely to be

Organisms that grow near deep‐sea volcanic vents are likely to be A) psychrophilic. B) psychrotrophic. C) mesophilic. D) thermophilic. Answer: D)...

When a microorganism is placed in a(n) __________ solution, water will enter into the cell and cause it to burst unless something is done to prevent this.

When a microorganism is placed in a(n) __________ solution, water will enter into the cell and cause it to burst unless something is done to prevent...

Organisms that are damaged by the normal atmospheric levels of oxygen (20%) but require oxygen at levels of 2-10% for growth are called

Organisms that are damaged by the normal atmospheric levels of oxygen (20%) but require oxygen at levels of 2-10% for growth are called A) facultative...

Organisms that do not require oxygen for growth but grow better in its presence are called

Organisms that do not require oxygen for growth but grow better in its presence are called A) facultative anaerobes. B) microaerophiles. C) aerotolerant. D)...

Which of the following is considered a cardinal growth temperature?

Which of the following is considered a cardinal growth temperature? A) the minimum temperature B) the maximum temperature C) the optimum temperature D)...

Which of the following can be used to estimate the number of microorganisms in a culture?

Which of the following can be used to estimate the number of microorganisms in a culture? A) direct counts of microbial cells B) counts of viable...

The length of the bacterial lag phase of growth can vary depending on

The length of the bacterial lag phase of growth can vary depending on A) the condition of the microorganisms. B) the nature of the growth medium. C)...

A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a __________ culture.

A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a __________ culture. A)...

Most bacterial and archaeal cells divide by

Most bacterial and archaeal cells divide by A) mitosis B) meiosis C) binary fission D) all of the above Answer: C) Binary Fissio...

Differential media make it easier to distinguish colonies of different microbes

Differential media make it easier to distinguish colonies of different microbes A) True B) False Answer: A) Tru...

Microbes that require higher CO2 levels that are found in air are called

Microbes that require higher CO2 levels that are found in air are called A) facultative anaerobes B) microaerophiles C) capnophiles D) aerobes E)...

Which of the following is not generally true about biofilms?

Which of the following is not generally true about biofilms? A) They may be considered microbial communities B) The organisms in them do not share...

Which of the following uses inorganic molecules such as H2S as an energy source?

Which of the following uses inorganic molecules such as H2S as an energy source? A) lithotrophs B) chemotrophs C) photoptrophs D) aerobes? Answer: B)...

An organic compound such as an amino acid or vitamin that cannot be synthesized by an organism and must be provided as a nutrient is called a

An organic compound such as an amino acid or vitamin that cannot be synthesized by an organism and must be provided as a nutrient is called a A) key...

Organisms that must obtain their carbon in organic form are called

Organisms that must obtain their carbon in organic form are called A) parasites B) photosynthesizers C) heterotrophs D) autotrophs Answer: C)...

Some microbes can transform N2 into usable compounds; this is achieved by the process of

Some microbes can transform N2 into usable compounds; this is achieved by the process of A) Photosynthesis B) Nitrogen fixation C) Nitrogen reduction D)...

Which of the following is an organic growth factor?

Which of the following is an organic growth factor? A) glucose B) vitamin B C) peptone D) Na2HPO4 E) H2O Answer: B) Vitamin ...

A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained

A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series....

Patients with indwelling catheters are susceptible to infections because

Patients with indwelling catheters are susceptible to infections because A) Injected solutions are contaminated. B) Their immune systems are weakened. C)...

Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours?

Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours? A) 3072 B) 1024 C) 243 D)...

An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through?

An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through? A) 64 B) 32 C) 6 D) 5 E) 4 Answer: D)...

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?

Which of the following is an example of a metabolic activity that could be used to measure microbial growth? A) Standard plate count B) Glucose consumption C)...

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt? A) Psychrophiles B) Facultative halophiles C) Anaerobes D)...

Which of the following is NOT a direct method to measure microbial growth?

Which of the following is NOT a direct method to measure microbial growth? A) Direct microscopic count B) Standard plate count C) Filtration D) Metabolic...

Which of the following is the best definition of generation time?

Which of the following is the best definition of generation time? A) The length of time needed for lag phase B) The length of time needed for a cell...

During which growth phase will gram‐positive bacteria be most susceptible to penicillin?

During which growth phase will gram‐positive bacteria be most susceptible to penicillin? A) Lag phase B) Log phase C) Death phase D) Stationary phase E)...

Which of the following pairs is mismatched?

Which of the following pairs is mismatched? A) Psychrotroph - growth at 37°C B) Thermophile - growth at 60°C C) Mesophile - growth at 25°C D) Psychrophile...

A culture medium consisting of agar, human blood, and beef heart is a

A culture medium consisting of agar, human blood, and beef heart is a A) Chemically defined medium. B) Complex medium. C) Selective defined medium. D)...

Most bacteria grow best at pH

Most bacteria grow best at pH A) 1. B) 5. C) 7. D) 9. Answer: C) 7, neutra...

In Figure 2, which sections of the graph illustrate a logarithmic change in cell numbers?

In Figure 2, which sections of the graph illustrate a logarithmic change in cell numbers? A) a and c B) b and d C) a and b D) c and d Answer: B)...

In Figure 2, which sections show a phase where the number of cells dying equals the number of new cells being produced?

In Figure 2, which sections show a phase where the number of cells dying equals the number of new cells being produced? A) a and c B) b and d C) a...

Thirty‐six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?

Thirty‐six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample? A)...

Which of the following is an advantage of the standard plate count?

Which of the following is an advantage of the standard plate count? A) Can readily count cells that form aggregates B) determines the number of viable...

Which of the following is an advantage of the direct microscopic count?

Which of the following is an advantage of the direct microscopic count? A) Can readily count organisms that are motile B) Easily counts dead cells C)...

The term facultative anaerobe refers to an organism that

The term facultative anaerobe refers to an organism that A) Doesn't use oxygen but tolerates it. B) Is killed by oxygen. C) Uses oxygen or grows without...

Salts and sugars work to preserve foods by creating a

Salts and sugars work to preserve foods by creating a A) Depletion of nutrients. B) Hypotonic environment. C) Lower osmotic pressure. D) Hypertonic...

The addition of which of the following to a culture medium will neutralize acids?

The addition of which of the following to a culture medium will neutralize acids? A) Buffers B) Sugars C) pH D) Carbon Answer: A) Buffers...