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Which of the following is the best definition of oxidative phosphorylation?
Electrons are passed through a series of carriers to O2. |
ATP is directly transferred from a substrate to ADP. |
Electrons are passed through a series of carriers to an organic compound. |
A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP. |
A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP.
Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?
circular chromosome |
ATP-generating mechanism |
binary fission |
cell wall |
70S ribosomes |
cell wall
Which microscope takes advantage of differences in the refractive indexes of cell structures?
phase-contrast microscope |
darkfield microscope |
compound light microscope |
fluorescence microscope |
electron microscope |
phase-contrast microscope
Which of the following pairs is mismatched?
iodine – mordant |
safranin – acid dye |
carbolfuchsin – basic dye |
crystal violet – basic dye |
alcohol-acetone - decolorizer |
safranin – acid dye
A ________ can be used to view the internal structures of cells in its native state?
scanning acoustic microscope |
fluorescence microscope |
phase-contrast microscope |
compound light microscope |
electron microscope |
phase-contrast microscope
Which drawing in the figure is streptococci?
D
________ allows a cell transport of substances from a lower to a higher concentration area.
Extracellular enzymes |
Simple diffusion |
Facilitated diffusion |
Active transport |
Aquaporins |
Active transport
An enzyme, citrate synthase, in the Krebs cycle is inhibited by ATP. This is an example of all the following except:
Feedback inhibition |
Noncompetitive inhibition |
Allosteric inhibition |
Competitive inhibition |
Competitive inhibition
Which of the following statements about gram-negative cell walls is FALSE?
They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids. |
They are sensitive to penicillin. |
They are toxic to humans. |
They protect the cell in a hypotonic environment. |
Their Gram reaction is due to the outer membrane. |
They are sensitive to penicillin.
Which of the graphs in the figure best illustrates the activity of an enzyme that is saturated with substrate?
C
Which of the following statements is incorrect about prokaryotic cells?
They lack membrane-enclosed organelles. |
Their DNA is not enclosed within a membrane. |
They reproduce by binary fission. |
They typically have a circular chromosome. |
They lack a plasma membrane. |
They lack a plasma membrane.
Cyanobacteria are a type of
chemoautotroph. |
chemoheterotroph. |
photoautotroph. |
photoheterotroph. |
photoautotroph.
Which compound is being reduced in the reaction shown in the figure?
NADH |
NAD+ |
α-ketoglutaric acid and NAD+ |
NADH and isocitric acid |
isocitric acid and α-ketoglutaric acid |
NAD+
In non-cyclic photophosphorylation, excited electrons ultimately ________.
flow through ATP synthase |
are used to form water |
combine with hydrogen ions and NADP+ to produce NADPH |
generate light within the spectrum of green wavelengths |
return to chlorophyll |
combine with hydrogen ions and NADP+ to produce NADPH
Which two staining techniques employ a mordant?
Gram stain and flagella stain |
Gram stain and acid-fast stain |
Simple stain and acid-fast stain |
Capsule stain and flagella stain |
Gram stain and capsule stain |
Gram stain and flagella stain
Which statements correspond to amphibolic pathways?
1. Anabolic and catabolic reactions are joined through common intermediate.
2. They are shared metabolic pathways.
3. Feedback inhibition can help regulate rates of reactions.
4. Both types of reactions are necessary but do not occur simultaneously.
2, 3, 4 |
1, 2, 3, 4 |
1 only |
1, 2, 3 |
2, 4 |
1, 2, 3
In the figure, where is ATP produced?
E
Microorganisms that catabolize sugars into ethanol and CO2 gas would most likely be categorized as ________.
homolactic fermenters |
aerobic respirers |
anaerobic respirers |
heterolactic fermenters |
alcohol fermenters |
alcohol fermenters
A virus measures 100 nm in length. What is its length in μm?
0.1 μm |
1 μm |
0.001 μm |
0.01 μm |
10 μm |
0.1 μm
Which of the following uses glucose for carbon and energy?
chemoautotroph |
chemoheterotroph |
photoautotroph |
photoheterotroph |
chemoheterotroph
Which of the following statements about anaerobic cellular respiration is not true?
The complete Krebs cycle is utilized. |
It involves the reduction of an organic final electron acceptor. |
It yields lower amounts of ATP when compared to aerobic respiration. |
It requires cytochromes. |
It generates ATP. |
It involves the reduction of an organic final electron acceptor.
Which of the following statements regarding metabolism is not possible?
ADP is formed in anabolic reactions. |
ATP is formed in catabolic reactions. |
Heat may be released in both anabolic and catabolic reactions. |
Anabolic reactions are degradative. |
Anabolic reactions are degradative.
Which of the following structures is not a functionally analogous pair?
Nucleus — nucleoid region |
9+2 flagella — bacterial flagella |
Chloroplasts — thylakoids |
Mitochondria — prokaryotic plasma membrane |
Cilia — pili |
Cilia — pili
The functions of the glycocalyx in bacteria include all of the following except:
Protection against dehydration |
Source of nutrition |
Increased virulence |
Biofilm formation |
Binary fission |
Binary fission
Which of the following does NOT achieve sterilization?
ethylene oxide |
dry heat |
autoclave |
pasteurization |
supercritical fluids |
pasteurization
Which of the following is NOT a product of transcription?
rRNA |
a new strand of DNA |
mRNA |
tRNA |
a new strand of DNA
During which growth phase will gram-positive bacteria be most susceptible to penicillin?
stationary phase |
death phase |
lag phase |
log phase |
The culture is equally susceptible during all phases. |
log phase
The reaction catalyzed by reverse transcriptase is
mRNA → cDNA. |
DNA → mRNA. |
tRNA → mRNA. |
mRNA → protein. |
DNA → DNA. |
mRNA → cDNA.
In the figure, which line best depicts a facultative anaerobe in the absence of O2?
b
If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of the radioactivity will be found in the cells'
proteins. |
phospholipids. |
DNA and proteins. |
DNA. |
DNA and phospholipids. |
DNA and proteins.
A source of heat-stable DNA polymerase is
Saccharomyces cerevisiae. |
Bacillus thuringiensis. |
Pseudomonas. |
Thermus aquaticus. |
Agrobacterium tumefaciens. |
Thermus aquaticus.
Which enzyme catalyzes the biochemical reaction: 2H2O2 → 2H2O + O2?
Catalase |
Oxidase |
Peroxidase |
Superoxide dismutase |
Catalase
Which of the following pairs of terms is mismatched?
germicide – kills microbes |
bacteriostatic – kills vegetative bacterial cells |
sterilant – destroys all living microorganisms |
fungicide – kills yeasts and molds |
virucide – inactivates viruses |
bacteriostatic – kills vegetative bacterial cells
A culture medium consisting of agar, peptone, and beef heart is a ________ medium.
chemically defined |
selective |
complex |
differential |
reducing |
complex
A gene is ________.
a sequence of nucleotides in RNA that codes for a functional product |
any random segment of DNA |
a three-nucleotide segment of DNA that code for an amino acid |
a sequence of nucleotides in DNA that codes for a functional product |
the RNA product of a transcribed section of DNA |
a sequence of nucleotides in DNA that codes for a functional product
Which of the following statements best describes the pattern of microbial death?
The pattern varies depending on the antimicrobial agent. |
The pattern varies depending on the species. |
All the cells in a culture die at once. |
Not all of the cells in a culture are killed. |
The cells in a population die at a constant rate. |
The cells in a population die at a constant rate.
Which of the following statements is not true regarding a bacterium that is R+?
R+ can be transferred to a cell of the same species. |
It possesses a plasmid. |
It is resistant to certain drugs and heavy metals. |
R+ can be transferred to a different species. |
It is F+. |
It is F+.
The biosafety level (BSL) for most introductory microbiology laboratories is
BSL-1. |
BSL-2. |
BSL-3. |
BSL-4. |
BSL-1.
The fact that people continue to be concerned about the safety of DNA technology can be attributed to which of the following?
People are suspicious of science, in general. |
It is impossible to prove something is safe under all conceivable conditions. |
Both that it is impossible to prove something is safe under all conditions and that science can only provide supporting evidence for hypotheses. |
There is mounting scientific evidence that DNA technology is unsafe. |
Science can definitively disprove hypotheses but can only provide supporting evidence for hypotheses. |
Both that it is impossible to prove something is safe under all conditions and that science can only provide supporting evidence for hypotheses.
Most fungi grow best at pH
5. |
7. |
1. |
14. |
9. |
5
In the figure, which model of the lac operon correctly shows RNA polymerase, lactose, and repressor protein when the structural genes are being transcribed?
d
A kitchen countertop has a spill of vegetable oil that was wiped up but a film remains. What should be the next step in disinfecting this surface?
isopropanol |
spray a disinfectant that contains a heavy metal |
10% bleach |
chlorhexidine containing solution |
warm soapy scrub |
warm soapy scrub
A suspension of 106 Bacillus cereus endospores was put in a hot-air oven at 170°C. Plate counts were used to determine the number of endospores surviving at the time intervals shown.
In the figure, the thermal death point for this culture is
170°C. |
50°C. |
15 minutes. |
30 minutes. |
The answer cannot be determined based on the information provided |
The answer cannot be determined based on the information provided
The following data were obtained by incubating gram-positive bacteria in nutrient medium + disinfectant for 24 hours, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth)
In the table, which disinfectant was bactericidal?
Doom |
K.O. |
Mortum |
Sterl |
The answer cannot be determined based on the information provided. |
Mortum
Culture 1: F+, leucine+, histidine+
Culture 2: F-, leucine-, histidine-
In the table, if culture 1 mutates to Hfr, what will be the result of conjugation between the two cultures?
1 will become F+, leu+, his+; 2 will become F+, leu+, his+ |
1 will remain the same; recombination may occur in 2 |
1 will become F-, leu+, his+; 2 will become Hfr, leu+, his+ |
They will both remain the same. |
The answer cannot be determined based on the information provided. |
1 will remain the same; recombination may occur in 2
An advantage of cDNA over genomic DNA is that it ________.
contains selectable markers |
is easy to isolate |
does not contain exons |
can form very large DNA fragment |
does not contain introns |
does not contain introns
Which of the following is NOT a desired characteristic of DNA vectors used in gene cloning procedures?
self-replication |
may replicate in several species |
circular form of DNA or integrates into the host chromosome |
has a selectable marker |
large size |
large size
One advantage of a viral vector over a plasmid vector is that the
viral vector can harbor a selection marker. |
viral vector can accept much larger pieces of DNA. |
plasmid vector is circular. |
the viral vector can accept larger pieces of DNA and the plasmid vector is circular. |
viral vector can accept a PCR fragment. |
viral vector can accept much larger pieces of DNA.
If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?
boiling for one hour |
oven at 121°C for one hour |
bleach |
hydrogen peroxide |
pressure cooker at 121°C for 15 minutes |
pressure cooker at 121°C for 15 minutes
All of the following methods are effective for destroying prions except:
Proteases |
Incineration |
Boiling |
NaOH + autoclaving at 134°C |
None of the answers are correct; each of these will destroy prions |
Boiling
Repair of damaged DNA, in some instances and mechanisms, might be viewed as a race between an endonuclease and
methylase. |
DNA polymerase. |
helicase. |
primase. |
DNA ligase. |
methylase.
Which of the following is not an agricultural product made by recombinant DNA technology?
Nitrogenase (nitrogen fixation) |
Glyphosate-resistant crops |
Frost retardant |
Bacillus thuringiensis insecticide |
Pectinase |
Pectinase
Microorganisms placed in a high concentration of salt and sugar environment will undergo osmotic lysis.
True |
False |
False
According to the operon model, for the synthesis of an inducible gene to occur, the ________.
protein repressor must not be synthesized |
substrate must bind to the enzyme |
protein repressor must bind to the operator |
substrate must bind to the protein repressor |
end-product must not be in excess |
substrate must bind to the enzyme
Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?
microwaves |
sunlight |
autoclave |
gamma radiation |
ultraviolet radiation |
gamma radiation
A population of bacterial cells carrying a desired plasmid is called a ________.
Southern blot |
PCR |
library |
vector |
clone |
clone
An experiment began with 4 bacterial cells in log phase and ended with 128 cells. How many times the cells divided?
64 |
6 |
4 |
32 |
5 |
5
If you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?
the tertiary structure of the protein |
the quaternary structure of the protein |
the primary structure of the protein |
the secondary structure of the protein |
The answer cannot be determined based on the information provided. |
the primary structure of the protein
Often, patients with indwelling catheters (long-term tubes inserted into body orifices for drainage, such as through the urethra and into the urinary bladder) are susceptible to infections because:
Infections can be transmitted from other people. |
Biofilms develop on catheters. |
Bacteria cause infections. |
Injected solutions are contaminated. |
Their immune systems are weakened. |
Biofilms develop on catheters.
A sample of milk is tested for its bacterial content in a plate count assay. A 1 ml sample of the milk is diluted in a 1:10 serial dilutions. 1ml 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 ________ cells per milliliter.
540 |
540,000 |
54,000 |
54 |
5,400 |
54,000
You observe a mass of amoeba-like cells that swarm together, form a stalk, and produce spores. This is a(n)
cellular slime mold. |
tapeworm. |
ascomycete. |
Euglenozoa. |
plasmodial slime mold. |
cellular slime mold
A feature that may be found in viruses but never in bacteria is
a sensitivity to antibiotics. |
they cannot reproduce themselves outside a host. |
the ability to pass through 0.22 micrometer pore filters. |
an ability to infect more than one type of host. |
may contain an RNA genome. |
may contain an RNA genome.
Which of the following is NOT a characteristic of spirochetes?
helical shape |
possess an axial filament |
gram-negative |
easily observed with brightfield microscopy |
found in the human oral cavity |
easily observed with brightfield microscopy
Fatty acid methyl ester analysis is commonly used in ________.
DNA fingerprinting |
serological identification methods |
DNA sequencing reactions |
bacterial identification |
bacterial identification
1. | 9+2 flagella |
2. | Nucleus |
3. | Plasma membrane |
4. | Peptidoglycan |
5. | Mitochondrion |
6. | Fimbriae |
In the table, which features are found in nearly all members of the Domain Eukarya?
1, 4, 6 |
2, 3, 5 |
1, 2, 5 |
3, 5 |
2, 3 |
2, 3, 5
Bacteriophages and animal viruses do not differ significantly in which one of the following processes?
Biosynthesis |
Release |
Uncoating |
Attachment |
Penetration |
Biosynthesis
This figure shows the results of a gel electrophoresis separation of restriction fragments of the DNA of different organisms.
In the figure, which two organisms are most closely related?
4 and 5 |
2 and 4 |
1 and 3 |
2 and 5 |
3 and 5 |
1 and 3
Actinomycetes differ from fungi in that actinomycetes
are chemoheterotrophs. |
lack a membrane-bounded nucleus. |
cause disease. |
require light. |
are decomposers. |
lack a membrane-bounded nucleus.
You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong?
deltaproteobacteria |
phototrophic bacteria |
gammaproteobacteria |
bacillales |
The answer cannot be determined based on the information provided. |
bacillales
A bacterial species differs from a species of eukaryotic organisms in that a bacterial species
breeds with its own species. |
does not breed with other species. |
has a limited geographical distribution. |
is a population of cells with similar characteristics. |
can be distinguished from other bacterial species. |
is a population of cells with similar characteristics.
Staphylococcus and Streptococcus can usually be differentiated by microscopic examination because of their ________.
endospore formation |
Gram stain reaction |
cell arrangement |
cell shape |
acid-fast reaction |
cell arrangement
Which of the following pairs are mismatched?
Actinomycetes — reproduce by fragmentation |
Archaea — extremophiles |
Cytophaga — a gliding, nonfruiting bacterium |
Chemoautotrophic bacteria — fix atmospheric nitrogen |
Dissimilatory sulfate-reducing bacteria — produce H2S |
Chemoautotrophic bacteria — fix atmospheric nitrogen
What contributes to antigenic shift in influenza viruses?
different virus subtypes |
ease of virus transmission |
a segmented genome |
attachment spikes |
worldwide distribution of the virus |
a segmented genome
In a direct ELISA test for COVID-19, the method is determining if ________ is/are present in the patient's sample by attempting to bind a labeled antibody to it.
SARS-CoV-2 or an antigen from the virus |
a bacteriophage that can infect a particular bacterial strain |
a known sequence of DNA from a pathogen |
antibodies against SARS-CoV-2 found in a patient's blood |
SARS-CoV-2 or an antigen from the virus
A definitive host harbors which stage of a parasitic cycle?
Miracidium |
Adult |
Larva |
Cyst |
All of the answers are correct. |
Adult
Which of the following pairs is mismatched?
Zygomycota – sporangiospores |
Ascomycota – conidiospores |
anamorphs – lack spores |
microsporidia – lack mitochondria |
Basidiomycota – basidiospores |
anamorphs – lack spores
Assume you have isolated a multicellular heterotrophic organism that produces coenocytic hyphae, motile zoospores, and cellulose cell walls. It is most likely a(n)
zygomycete fungus. |
oomycote alga. |
green alga. |
ascomycete fungus. |
tapeworm. |
oomycote alga.
Which of the following is necessary for replication of a prion?
lysozyme |
DNA polymerase |
RNA |
DNA |
PrPSc |
PrPSc
The application of phage typing is based on the fact that ________.
bacteria are destroyed by viruses |
viruses cause disease |
bacterial viruses attack only members of a specific species |
Staphylococcus causes infections |
phages and bacteria are related |
bacterial viruses attack only members of a specific species
What is not true regarding viruses that infect plants?
They are morphologically similar to animal viruses. |
They must enter through a wound or be introduced by an inset feeding. |
They can sometimes be cultured in insect cells. |
They can spread via pollination. |
They are often cultured in embryonated chicken eggs. |
They are often cultured in embryonated chicken eggs.
The mechanism whereby an enveloped virus leaves a host cell is called
abduction. |
lysogeny. |
transduction. |
budding. |
penetration. |
budding
Which of the following statements regarding lichens is FALSE?
Lichens are a mutualistic relationship between a fungus and a protozoan. |
The algal partner produces carbohydrates that are absorbed by the fungal partner. |
Lichens are often the first life form to colonize rock or soil. |
Lichens represent a mutualistic relationship between a fungus and an alga. |
The fungal partner provides a means of attachment and protects the algal partner from desiccation. |
Lichens are a mutualistic relationship between a fungus and a protozoan
Which of the following arthropods does NOT transmit diseases by sucking blood from a human host?
mosquitoes |
houseflies |
lice |
kissing bugs |
fleas |
houseflies
Which of the following statements about members of the Kingdom Plantae is false?
They are composed of eukaryotic cells. |
They synthesize organic molecules. |
They use organic carbon sources for their metabolism. |
They are photosynthetic. |
They are multicellular. |
They use organic carbon sources for their metabolism.
If a larva of Echinococcus granulosus is found in humans, humans are the
definitive host. |
infected host. |
reservoir. |
intermediate host. |
None of the answers is correct. |
intermediate host
Which of the following is NOT utilized to culture viruses?
laboratory animals |
culture media |
animal cell cultures |
embryonated eggs |
bacterial cultures |
culture media
Which of the following is the most effective control for malaria?
treating patients |
vaccination |
eliminate Anopheles mosquitoes |
eliminate the intermediate host |
None of these is an effective control. |
eliminate Anopheles mosquitoes
The genus of bacteria that are particularly problematic in hospital settings due to their ability to grow in solutions with minute traces of unusual carbon sources is
Staphylococcus. |
Pseudomonas. |
Vibrio. |
Campylobacter. |
Legionella. |
Pseudomonas
The most conclusive evidence that viruses cause cancers was provided by
cancer that developed in chickens following injection of cell-free filtrates. |
the presence of antibodies against viruses in cancer patients. |
treating cancer with antibodies. |
some liver cancer patients having had hepatitis. |
finding oncogenes in viruses. |
cancer that developed in chickens following injection of cell-free filtrates.
Into which group would you place a photosynthetic cell that lacks a nucleus?
Protista |
Animalia |
Fungi |
Bacteria |
Plantae |
Bacteria
Which of the following best describes the bacterial group found primarily in the intestines of humans?
Gram-negative aerobic rods and cocci |
Facultatively anaerobic gram-negative rods |
Gram-positive cocci |
Endospore-forming rods |
Aerobic, helical bacteria |
Facultatively anaerobic gram-negative rods