Microbiology Final Review
Bacterium Y, which has a generation time of 30 minutes, was inoculated in a sterile nutrient broth. After 3 hours of incubation, there are 7 x 10^5 cells of Bacterium Y were inoculated in the broth?
((7x10^5)/(2^6))= 1.1 x 10^4 cells
Decimal Reduction Time
(D value) Time required for 90% of a microbial population to be killed under specific conditions
Which statements describe DNA replication in bacteria?
-Both the strands act as templates . -The lagging strand is synthesized discontinuously. -Elongation of the lagging strand proceeds away from replication fork. -The leading strand is synthesized continuously.
Which are true about purple sulfur and green sulfur bacteria?
-Both use hydrogen sulfide as a source of electrons. -Both are photosynthetic bateria. -Both preferentially use organic molecules as an electron source.
What are the inputs of the dark reactions of photosynthesis?
-CO2 -NADPH -ATP
Which of the following are actions that can lead to development of antimicrobial resistance?
-Discontinuing antimicrobials as soon as you feel better -Taking antimicrobials left over from old prescriptions -Using antibacterial agents to treat viral infections
What can you do to help minimize the development of population of bacteria resistant to antibiotics?
-I shall not save antibiotics for next time -I shall use antibiotics as prescribed -I shall not use another person's prescription.
Which of the following statements are true about the lac operon?
-If glucose is absent and lactose is present, there is transcription. -If both glucose and lactose are absent, there is no transcription. -If glucose is present and lactose is absent, there is no transcription.
Which statements are true about pilus?
-It is shorter than flagellum. -It is longer than fimbriae. -Only one or two are present per cell.
Which of the following are economic importance of fungi?
-Some fungi are useful tools in rDNA technology. -Some fungi cause diseases in humans. -Some fungi can synthesize antibiotics like penicillin. -Some fungi are used in making beer and wine.
What are the methods used to maintain stock cultures?
-Storage in a functioning refrigerator -Freeze drying -Freezing at -70 C
Which statements are true about cyanobacteria?
-They use water as the reducing agent. -They reduce carbon dioxide to glucose. -They do not deposit sulfur just like the purple and green bacteria. -They perform oxygenic photosynthesis.
A spoon has 100,000 cells of bacteria on its surface. If you treat the spoon with a bactericidal agent that has a D value of 2.5 minutes, how many minutes will it take to reduce the number of bacteria to 10. Your answer must be numeric with its unit like 2 min
10 min
What is the time and temperature requirement of sterilization in the autoclave?
121 C for 15 min
What is the time and temperature requirement of sterilization in dry heat ovens?
160 C-170 C for 2-3 h
Purple Bacteria
A group of anoxygenic phototrophs that are red, orange, or purple in color
Kinetoplastids
A group of flagellated protozoa that have a distinct mass in their large, single mitochondrion
Diplomonads
A group of flagellated protozoa that lack both mitochondria and hydrogenosomes
Acid-Fast Staining
A procedure used to stain certain microorganisms, particularly Mycobacterium species, that do not readily take up dyes
Scientific Method
A process of formulating a testable explanation for a question, doing controlled experiments to test that explanation, and then publishing the methods, results, and conclusions
F Pilus (Sex Pilus)
A protein appendage required for DNA transfer in the process of conjugation
Carbon Catabolite Repression (CCR)
A regulatory mechanism that allows cells to prioritize their use of carbon/energy sources
Which of these bacteria have plasmid containing gene that encodes ability to synthesize plant growth hormone thus resulting in tumor?
Agrobacterium
What are the two genera of bacteria associated with plants?
Agrobacterium and Rhizobium
What are two genera of bacteria associated with plants?
Agrobacterium and Rhizobium
F' Plasmid
An F plasmid that carries chromosomal genes
Viroid
An infectious agent of plants that consists only of RNA.
What is a prion?
An infectious agent that is made up of protein only.
Emerging infectious disease (EID)
An infectious disease that is increasing in incidence or geographic range
Prion
An infectious protein that causes a neurodegenerative disease.
Temperate Phage
Bacteriophage that can either become integrated into the host cell DNA as a prophage or direct a productive infection that leads to cell lysis
Lytic (Virulent) Phages
Bacteriophages that lyse their host
Nucleotide
Basic subunit of RNA or DNA consisting of a purine or pyrimidine covalently bonded to ribose or deoxyribose, which is covalently bound to a phosphate molecule
The fungus (yellow in color) shown in figure 12 belongs to what major group of fungi?
Basidiomycete
Which of the following statement is true?
Basidiospores are in the basidium in the basidiocarp.
What is the effect of hypotonic solution on cells without cell walls?
Cells swell then burst
What is the effect of a hypotonic solution on cells with cell walls?
Cells swell, but will not burst
HFR (High Frequency of Recombination) Cells
Cells that have the F plasmid integrated into their chromosome, allowing them to begin transferring the chromosome by conjugation
Endoflagella (Axial Filaments)
Characteristic structures of motility in spirochetes
Endergonic
Chemical reaction that requires a net input of energy because the products have more free energy than the starting compounds
Oxidation-Reduction (Redox) Reactions
Chemical reactions in which one or more electrons is transferred from one molecule to another
Diplococci
Cocci that typically occur in pairs
Quorum Sensing
Communication between bacterial cells by means of small molecules, permitting the cells to sense the density of cells
Energy Source
Compound that a cell oxidizes to harvest energy; also called an electron donor
Nitrogen Fixation
Conversion of nitrogen gas to ammonia
What is the device that counts cells as they interrupt an electrical current?
Coulter counter
Red tide is caused by the overgrowth of ______.
Dinoflagellates
Spontaneous Generation
Discredited belief that organisms can arise from nonliving matter
Mycosis
Disease caused by fungal infection.
Pathogen
Disease-causing organism or agent
Microfilter (Membrane Filter)
Filter that has a pore size small enough to trap microorganisms but still allow liquids to pass through
Proton Motive Force
Form of energy generated as an electron transport chain moves protons across a membrane to create a chemiosmotic gradient
Proton Motive Force
Form of energy generated as an electron transport chain moves protons across a membrane to create a chemiosmotic gradient.
Restriction Fragments
Fragments generated when DNA is cut with restriction enzymes
Nitrifiers
Group of Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrate
Retroviruses
Group of viruses that have a single-stranded RNA genome; their enzyme reverse transcriptase synthesizes a DNA copy that is then integrated into the host cell chromosome
Reading Frames
Grouping of nucleotides in sequential triplets; an mRNA molecule has three possible reading frames, but only one is typically used in translation
Infection
Growth and multiplication of a parasitic organism or virus in or on the body of the host with or without the production of disease
Leading Strand
In DNA replication, the DNA strand that is synthesized as a continuous fragment
Lagging Strand
In DNA replication, the strand that is synthesized as a series of fragments
Contrast
In microscopy, the number of different visible shades in a specimen
Flagellum
In prokaryotic cells, a long protein appendage composed of subunits of flagellin that provides a mechanism of motility. In eukaryotic cells, a long whip-like structure composed of microtubules in a 9+2 arrangement that provides a mechanism of motility
Terminator
In transcription, a DNA sequence that stops the process
Virucide
Inactivates viruses
Pediculosis
Infestation with lice
What is the mode of action of trimethoprim?
Inhibits folate synthesis
Below are ingredients of a culture medium. What type of culture medium is it based on form and composition? -Peptone -3g -Beef extract -5g -Distilled water -1000mL
Liquid and complex
Drugs with (longer/shorter) half-life are given to patients less frequency?
Longer
Whose experiment finally disproved the theory of spontaneous generation?
Louis Pasteur
Membrane filtration is used to count cells in samples with (low or high) population density.
Low
Minimum Bactericidal Concentration (MBC)
Lowest concentration of a specific antimicrobial medication that kills 99.9% of cells in a culture of a given bacterial strain in vitro
Minimum Inhibitory Concentration (MIC)
Lowest concentration of a specific antimicrobial medication that prevents the growth of a given microbial strain in vitro
First-Line Drugs
Medications preferred because they are most effective as well as least toxic
Second-Line Drugs
Medications that are second choice because they are toxic or less effective
Phagolysosome
Membrane-bound vacuole generated when a phagosome fuses with lysosomes
Phagosome
Membrane-bound vacuole that contains the material engulfed by a phagocyte
Electron Microscope
Microscope that uses electrons instead of light and can magnify images in excess of 100,000×
Compound Microscope
Microscope that uses multiple magnifying lenses, thereby visually enlarging an object by a factor equal to the product of the magnification of each lens
Light Microscope
Microscope that uses visible light and a series of lenses to magnify objects
Antigen
Molecule that reacts specifically with an antibody or lymphocyte
Chemotaxis
Movement of a cell toward or away from a certain chemical in the environment.
Osmosis
Movement of water across a membrane from a dilute solution to a more concentrated solution
Chromosome in bacteria is located in the region in the cytoplasm called ______.
Nucleoid
Cytopathic Effect
Observable change in a cell in vitro caused by a viral action such as cell lysis
Psychrotrophs
Organism that has an optimum temperature between 15°C and 30°C
Photoautotrophs
Organisms that use light as the energy source and CO2 as the major carbon source
Photoheterotrophs
Organisms that use light as the energy source and organic compounds as the carbon source
Microorganisms
Organisms too small to be seen with the naked eye
Convergent Evolution
Process that results in organisms with similar characteristics, developed independently as the organisms adapted to similar environments
Signal Transduction
Process that transmits information from outside of a cell to the inside, allowing that cell to respond to changing environmental conditions
Endocytosis
Process through which cells take up particles by enclosing them in a vesicle pinched off from the cell membrane
Primer
RNA molecule that initiates the synthesis of DNA
Photosynthesis
Reactions used to harvest the energy of light to synthesize ATP, which is then used to power carbon fixation
Intrinsic (Innate) Resistance
Resistance due to inherent characteristics of the organism.
Diatomaceous Earth
Sedimentary soil composed largely of the remains of diatoms; contains large amounts of silicon
Prokaryote
Single-celled organism consisting of a prokaryotic cell; members of the domains Bacteria and Archaea are prokaryotes.
All of the following are true about fungi except_____.
Some are prokaryotes and some are eukaryotes.
Coccus
Spherical-shaped bacterial cell
Asexual spores of zygomycetes are located in _____.
Sporangium
Simple Staining
Staining technique that uses a basic dye to add color to cells,
Which of the following groups of microorganisms oxidize organic compounds and produce a product that smell like a rotten egg?
Sulfur and Sulfate-reducing bacteria
Mycelium
Tangled, mat-like mass of fungal hyphae
F+ refers to a cell containing ______.
The F plasmid
Hybridization
The annealing of two complementary strands of DNA from different sources to create a hybrid double-stranded molecule
In Ames test, what does it mean when a chemical can cause Salmonella typhimurium his- to revert to his+?
The chemical is a mutagen.
Microbiome
The community of microorganisms, as well as their genetic information, in a given environment
Metagenomics
The cultivation-independent study of microbial communities or their members by analyzing the total microbial genomes in a sample taken directly from an environment
Sterilization
The destruction or removal of all microbes through physical or chemical means.
LD50
The dose that kills approximately 50% of hosts
Cytoskeleton
The dynamic filamentous network that provides structure and shape to cells
3' end
The end of a nucleotide strand that has a free hydroxyl group on the number 3 carbon of the sugar
5' end
The end of a nucleotide strand that has a phosphate group attached to the number 5 carbon of the sugar
Adenosine Triphosphate (ATP)
The energy currency of cells. Hydrolysis of the bonds between its phosphate groups can be used to power endergonic (energyconsuming) reactions.
Normal microbiota
The group of microorganisms that colonize the body surfaces but do not usually cause disease
Lumen
The interior of an organ or organelle
Human Genome Project
The now-completed undertaking to sequence the human genome
Chlorophylls
The primary light-absorbing pigments used in photosynthesis
Sporulation
The process of producing a spore
Genotype
The sequence of nucleotides in an organism's DNA.
Global Control
The simultaneous regulation of numerous unrelated genes
Mycology
The study of fungi
Ecophysiology
The study of the physiological mechanisms organisms use to thrive in a given environment
Generation Time
The time it takes for a population to double in number.
What is one DISADVANTAGE associated with the use of broad-spectrum antibiotics?
They kill normal mircobiota
Hypha
Thread-like structure that characterizes the growth of most fungi and some bacterial species
In eukaryotes, light reactions of photosynthesis take place in the _____.
Thylakoid in chloroplast
Gene Expression
Transcribing and then translating the information in DNA to produce the encoded protein
What happens during the energy investment stage of glycolysis?
Two ATP are used up.
Thymine Dimers
Two adjacent thymine molecules on the same strand of DNA joined together through covalent bonds
Petri Dish
Two-part dish of glass or plastic often used to contain medium solidified with agar, on which bacteria are grown
Ribosomal RNA (rRNA)
Type of RNA molecule present in ribosomes.
Low-Level Disinfectants
Type of chemical used to destroy fungi, enveloped viruses, and vegetative bacteria except mycobacteria
Bacteriochlorophylls
Type of chlorophyll used by purple and green bacteria; absorbs wavelengths of light that penetrate to greater depths and are not used by other photosynthetic organisms
Fimbria
Type of pilus that enables cells to attach to a specific surface
Photoreactivation (Light Repair)
Using the energy of light to break the covalent bonds joining thymine dimers, thereby restoring the DNA to its original state
Protists
Usually single-celled eukaryotes that are not fungi, plants, or animals.
Enveloped Viruses
Viruses that have a lipid bilayer surrounding their nucleocapsid
Which of the following statements about viruses is FALSE?
Viruses use their own enzymes to replicate.
Which is the major composition of fungal cell wall?
chitin
What is the resting heat sensitive cell for nitrogen fixation formed by Azotobacter sp.?
cyst
Fungi cause human illness in three general ways. If the fungi grow on or in the human body causing an illness, what general way it is?
infection
Which statements are true about the Calvin cycle in plants and algae?
-ATP and NADPH are required. -CO2 is reduced to glucose. -It uses the products of the light reactions.
Differentiate aerobic respiration from anaerobic respiration based on number of ATP produced per molecule of glucose and final electron acceptors
-Aerobic respiration generates more ATP than anaerobic respiration -Aerobic respiration uses oxygen as final electron acceptor while anaerobic respiration uses sulfates and carbonates
Which of the following are autotrophs?
-All algae -Some archaea -Some bacteria
Which of these microorganisms are heterotrophs?
-All fungi -Some bacteria -All protozoa
Which of the following statements describe the microorganisms under domain Archaea and Bacteria?
-All of them are unicellular. -All of them do not have membrane-enclosed organelles. -Some of them can photosynthesize. -All of them have DNA located in the nucleoid
Which of the following processes do not use oxygen to generate ATP?
-Anaerobic cellular respiration -Ethanol fermentation -Lactic acid fermentation
What are the functions of glycocalyx?
-Attachment cells to each other and to the environment. -Protects the cells from desiccation. -Protects the cells from the body's defensive cells such as WBC.
Which of the following statements is true?
-Autoclaving cannot destroy prions. -A high level disinfectant can sterilize. -Low number of endospores may remain in semi-critical items. -Critical items must be sterilized before use.
Give the similarities of yeasts and molds.
-Both are heterotrophs -Both are eukaryotic -Both are fungi
What are true about purple and green sulfur bacteria?
-Both preferentially use organic molecules as an electron source -Both are photosynthetic bacteria
Which of the following statements describe an enzyme?
-Enzyme is not consumed after the reaction -Enzyme speeds up a chemical reaction in living cells -Enzyme has an active site to where substrate binds
Which of the following statements describe an enzyme?
-Enzyme is very specific on its substrate. -Enzyme has an active site to where substrate binds. -Enzyme is not consumed after the reaction. -Enzyme speeds up a chemical reaction.
Differentiate eukaryotic chromosome from prokaryotic chromosome.
-Eukaryotic chromosome is linear while prokaryotic is typically circular. -Eukaryotic chromosome is diploid while prokaryotic chromosome is haploid. -Eukaryotic chromosome contains histone proteins while prokaryotic chromosome contains non-histone proteins.
What are the functions of bacterial cell membrane?
-For ATP production -For photosynthesis -For regulation the transport of materials -For synthesis of substances
What are the functions of prosthecate in prosthecate bacteria?
-For attachment -For absorption of nutrients
Which of the following statements describe a Gram-positive cell wall?
-It has thicker peptidoglycan than Gram-negative -It does not have endotoxin -Porin proteins are absent
Which of the following describe the virus that caused COVID-19?
-It is an enveloped virus. -It is a single-stranded virus. -It is a corona virus.
Which of the following are true about the chromosome of bacteria?
-It is composed of DNA and non-histone proteins. -Typically, it is circular in shape. -It is double stranded.
Which of the following describe the genetic code?
-It is nearly universal. -An amino acid can be coded by more than one codon. -There are 61 codons coding for amino acids.
Which statements describe glycolysis?
-It occurs in the cytoplasm of eukaryotic and prokaryotic cells -It generates a net of 2 ATP per glucose molecule -It produces 2 NADH from the breakdown of one glucose to two pyruvic acid
Which of these structures are present only in Gram-negatives and absent in Gram-positives
-Lipid A -LPS
What are the outputs of the dark reactions of photosynthesis?
-NAD+ -ADP -Glucose
What are the differences between Needham and Spallanzani's experiments?
-Needham briefly heated his broth but Spallanzani heated the broth longer -Needham covered his flasks with cork but Spallanzani covered completely by melting the glass necks
What are the differences between Needham's and Spallanzani's experiments?
-Needham briefly heated his broth but Spallanzani heated the broth longer. -Needham covered his flasks with cork but Spallanzani covered completely his flask by melting the glass necks.
Which of the following substances are present only in gram negative cell walls?
-Outer membrane -Endotoxin
Amino acids are synthesized from precursor metabolites of __________.
-Pentose phosphate pathway -Glycolysis -Kreb's cycle
Sex pilus is essential for which of the following?
-Plasmid transfer conjugation in bacteria -Hfr conjugation in bacteria
Which of the following can cause algal bloom?
-Pollution from untreated sewage. -Run off of fertilizers along waterways and coastlines. -More nutrients are brought to the surface from the bottom due to upwelling of water cause by warmer temperature.
Which of the following statements describe Gram-positive cell wall?
-Porin proteins are absent. -It does not have endotoxin. -It has thicker peptidoglycan than Gram-negative.
Which of the following Do Not produce oxygen during photosynthesis?
-Purple bacteria -Green bacteria
Which statements describe pyruvate oxidation?
-Pyruvic acids are oxidized -Pyruvic acids are decarboxylated
Describe methanogens.
-Reduce carbon dioxide to methane -Anaerobic archaea -Can be isolated from sewage, swamps and marine sediments samples -oxidize hydrogen gas to produce methane
Which of the following statements describe conjugation in bacteria?
-The donor bacterium is F+ -DNA passes from the donor bacterium to recipient bacterium through the sex pilus -The recipient bacterium is F-.
Explain why is adding high amount of salt and sugar prevent food spoilage caused by microorganisms?
-The process removes water from microorganisms killing them. -Adding high amount of salt and sugar creates a hypertonic environment to microorganisms.
Which statements are true about the synthesis of the leading strand?
-The strand is synthesized using only one RNA primer. -The strand is synthesized towards the fork.
Which are true statements about a DNA molecule?
-The two strands are complementary to each other; adenine-thymine and cytosine-guanine. -The strands composing the DNA molecule are held by hydrogen bonds. -It is composed of two strands. -The strands composing the DNA molecule are antiparallel.
Which are true statements about plasmids?
-They are circular in shape. -They are composed of DNA. -They are double stranded.
Why are anaerobes killed when exposed to oxygen?
-They cannot produce catalase and superoxide dismutase. -Because when exposed to oxygen they can produce reactive oxygen species (ROS).
Which of the following are true about subunit vaccines?
-They do not pose a risk for causing disease. -They are made up of parts of bacteria or viruses. -They are safer compared to vaccines made up of inactivated microbes.
Which of the following statements describe viruses?
-They have DNA or RNA as their genetic material. -They are obligate intracellular parasite. -They are acellular
Which are true about transposons?
-They may cause knockout mutations. -They are informally known as jumping genes. -They were first recognized in corn.
Which of the following are goals of recombinant DNA technology?
-To create organisms capable of producing useful products -To combine genetic material from one organism to produce new useful organisms -To be able to remove or correct damaging traits in humans -To eliminate undesirable traits from livestock or crops
Which of the following are horizontal gene transfers in bacteria?
-Transduction -Transformation -Conjugation
Which of the following will result to nucleotide substitution?
-alkylating agents -base analogues
How can you control microorganisms?
-by killing microorganisms -by inhibiting growth of microorganisms -by removing microorganisms
Which of the following antibiotics inhibit the cross-linking of the peptidoglycan chains?
-cephalosporin -glycopeptides -penicillins
Which of the following transport processes need transport proteins?
-facilitated diffusion -group translocation -sodium-potassium pump
Which of these structures are present only in Gram-negatives and absent in Gram-positives?
-lipid A -LPS
Which drugs are effective against Mycobacterium species?
-rifampin -isoniazid -ethambutol -pyrazinamide
What are some signs of viral infections in plants?
-stunted growth -yellowing of leaves -tumor formation
What microorganisms are killed by low level disinfectants/ and antiseptics?
-trophozoites -most Gram positive and Gram-negative bacteria -enveloped viruses -large non-enveloped viruses
Typically, how many chromosome/s is/are there in bacteria? Your answer must be numeric only such as 2.
1
Match the microbial control methods on the left with their uses. 1. UV radiation 2. filtration of fluid 3. ionizing radiation 4. incineration A. destroys microorganisms in the air B. sterilizes heat-sensitive medical equipment C. sterilizes wire loops D. sterilizes heat sensitive medications
1-A 2-D 3-B 4-C
Match the antimicrobial medications to their target structures in bacteria. 1. B lactams antibiotics 2. Polymixins 3. Fluoroquinolones 4. Tetracyclines 5. Sulfonamides A. cell wall B. DNA C. ribosomes D. cell membrane E. enzymes
1-A 2-D 3-B 4-C 5-E
Match the food preservation methods to their actions against microorganisms. 1. Weak organic acids 2. Refrigeration and freezing 3. Adding salts and sugar 4. Drying A. creates hypertonic environment B. altering the function of their cell membrane C. slowing or stopping enzyme reactions D. lowering the water activity below the minimum
1-B 2-C 3-A 4-D
Match the parts to their functions. 1. Ribosomes 2. Nucleus 3. Endoplasmic reticulum (smooth and rough) 4. Golgi bodies 5. Mitochondria A. for transport within the cell B. for protein synthesis C. ATP production D. contains the cell's genetic instructions (DNA) E. receives, processes, and packages large molecules for export
1-B 2-D 3-A 4-E 5-C
Match the phases of bacterial growth to their descriptions 1. Lag phage 2. Log phase 3. Stationary phase 4. Death phase 5. Phase of prolonged decline A. number of cells that are multiplying equals the number of cells that are dying B. enzymes required for growth are synthesized C. survivors have adapted to tolerate worsened conditions D. number of cells that are dying is greater than the number of cells that are multiplying E. cells divide at a constant rate
1-B 2-E 3-A 4-D 5-C
Match the disease with their causal agents. 1. walking pneumonia 2. whooping cough 3. syphilis 4. Lyme disease 5. chancroid A. Bordetella pertussis B. Haemophilus ducreyi C. Mycoplasma pneumoniae D. Treponema pallidum E. Borrelia burgdorferi
1-C 2-A 3-D 4-E 5-B
Match the types of microorganisms based on temperature to their characteristics. 1. Psychrotrophs 2. Mesophiles 3. Thermophiles 4. Hyperthermophiles A. grow in hot springs and compost heaps B. grow in the human body C. cause spoilage of refrigerated foods D. can grow in the wall of hydrothermal vents
1-C 2-B 3-A 4-D
Match the structures in bacteria to their functions. 1. Flagella 2. Fimbriae 3. Inclusions 4. Plasma Membrane 5. Capsule A. for attachment B. protection from defensive cells (white blood cells) C. for storage of substances D. ATP production E. for movement
1-E 2-A 3-C 4-D 5-B
Match the examples to their method (terms) of microbial control 1. Plates and silverwares are washed in boiling water in campus dining hall 2. You wash your hands with plain soap and water. 3. Heat is used to kill potential pathogens in milk. 4. An autoclave is used to prepare nutrient agar. 5. You apply hand sanitizer (alcohol) in your hands. A. degerming B. antisepsis C. sterilization D. pasteurization E. sanitization
1-E 2-A 3-D 4-C 5-B
Bacterium Y, which has a generation time of 30 minutes, was inoculated in a sterile nutrient broth. After 3 hours of incubation, there are 7 x 105 cells of Bacterium Y in the broth. How many cells of Bacterium Y were inoculated in the broth? Your answer must be in scientific notation with units such as 1.6 x 10^2 cells. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^2 cells, type 1.7 x 10^2 cells. Put a space before and after the x. The x is lower case.
1.1 x 10^4 cells
E.coli growth in MacConkey agar is red. 0.1 ml of a urine sample diluted to 10^-2 was plated in MacConkey agar in duplicated. After 24 h incubation, there were 10 red colonies and 20 yellow colonies in one plate and in the other plate, there were 30 yellow colonies and 20 red colonies. Determine cfu/ml E.coli in the urine sample.
1.5 x 10^4 cfu/ml
You are using a Petroff-Hausser counting chamber to determine the number of cells in a liquid culture. After diluting the original sample 10-fold, you place the dilution into the chamber. You count an average of 15 cells in five different squares. How many cells per mL were present in your original sample? Your answer must be in scientific notation such as 1.0 x 10^2. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cells, type 1.7 x 10^5 cells. Put a space before and after the x. The x is lower case.
1.9 x 10^8 cells
Refer to figure 1. What is the final dilution of tube 2? Your answer must be in fraction such as 1/10.
1/1000
Refer to the figure below. What is the final dilution of tube 2?
1/1000
An object has 1 x10^6 bacteria. If a process kills 90% of bacterial cells every 4 minutes, how many living cells of bacteria are there after 20 minutes Your answer must be numeric with its description such as like 10 cells
10 cells
In the figure below, how many cells survive after 2 minutes? Your answers must be numeric with its description such as 1000 cells.
100 cells
In the figure below, how many cells survive after 5 minutes?
10^4 cells
In the figure below, how many cells survive after 2 minutes? Your answers must be numeric with its description such as 10^5 cells
10^7 cells
Guacamole can be pasteurized by exposure to ________.
130,000 psi pressure
A blood sample of a patient with gentamicin was analyzed for the concentration of gentamicin using diffusion bioassay. Using figure 7, what is the zone of clearing if the concentration of gentamicin is observed to be 20 ug/mL.
17 mm
A bacterial culture in exponential growth contained 10^4 cells/mL at time zero and 10^10 cells/mL after 6 hours. What is the generation time? Your answer must be numeric with a unit (minutes) such as 10.1 minutes. Round your answer to the nearest 10th.
18.0 minutes
A bacterial culture's exponential growth contained 10^4 cells/mL after 6 hours. What is the generation time? Your answer must be numeric with unit (minutes) such as 10.1 minutes
18.1 minutes
A technician wanted to determine lactose-fermenting bacteria in a drinking water sample. Sp, he filtered 200 mL of the sample in a membrane filtration until that does not allow the passage of bacteria. The filter paper was put on the surface of MacConkey agar. After incubation, he observed 2 red colonies and 4 colorless colonies. How many lactose-fermenting bacteria are there per 100mL of drinking water?
2
In the figure below, how many D values are needed to reduce the number of survivors to 100?
2
Put the following events in order to describe plasmid conjugation in bacteria. 1. Fusion of cell membrane of donor cell and recipient cell 2. Attachment of sex pilus 3. Transfer of F factor 4. Sex pilus contracts pulling donor cell and recipient cell together
2-4-1-3
A pure culture in the exponential growth phase has a bacterial concentration of 6.4 x 10^8 cells/ml. If the bacterium has a generation time of 1 h, how long ago was the cell concentration 8.0 x 10^7 cells/ml? Your answer must be numeric with a unit such as 2 hours.
3 hours
In the figure below, how many D values are needed to reduce the survivors to 1? Your answer must be numeric only such as 3
4
A clinical microbiologist added 1 g of feces to tube 1 containing 99 ml saline. After mixing thoroughly the suspension, he removed 1 ml and added it to tube 9 ml saline. He then plated 0.1 ml from tubes 1 and 2 in duplicated in nutrient agar . After 24h incubation, he counted 400 and 450 colonies in the plates added with aliquot from tube 1 and 39 and 45 colonies in the plates added with aliquot from tube 2. Determine cfu/g of feces.
4.2 x 10^5cfu/g
One g of fecal matter was suspended in 9 mL saline solution (tube 1). After mixing gently but thoroughly throughout, one mL from tube 1 was removed and added to tube 99 mL saline solution (tube 2). One mL suspension from tube 2 was plated in nutrient agar and after 24 h incubation, 45 bacterial colonies were counted. Determine cfu/g bacteria in the fecal sample.
4.5 x 10^4 cfu/g
One g of fecal matter was suspended in 9 ml saline solution (tube1). After mixing gently but thoroughly, one ml from tube 1 was removed and added to a tube with 99 ml saline solution (tube 2). One ml suspension from tube 2 was plated in nutrient agar and after 24 h incubation, 45 bacterial colonies were counted. Determine cfu/g bacteria in the fecal sample. Your answer must be in scientific notation such as 1.0 x 10^2. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cfu/g, type 1.7 x 10^5 cfu/g. Put a space before and after the x. The x is lower case.
4.5 x 10^4 cfu/g
In figure 5, three sets of five tubes are prepared. The 1st set is inoculated with 10mL of sample, the 2nd set with 1mL of sample, and 3rd set with 0.1 mL of sample. After incubation at 37oC 24 h, positive results (red to yellow) for each set are observed, determine MPN.
49
Refer to the figure below. Figure A shows a normal bacteria expressing the gene. The sequence of polypeptide is Met-Lys-Phe-Gly. In figure 8, a point mutation occurred, a T was incorporated instead of C. What is the sequence of nucleotides of the mutant mRNA? The upper strand is used for transcription.
5' AUG AAG UUU AGC UAA 3'
What is the nucleotide sequence of the mRNA if the lower strand of the hypothetical DNA below is used to make mRNA? 5'ATG-CAT-TTT-GTA3'
5' AUG-CAU-UUU-GUA 3'
Refer to figure 2 and determine cfu/mL bacteria in the sample. Your answer must be in scientific notation with a unit such as 1.0 x 10^2 cfu/mL. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cfu/mL, type 1.7 x 10^5 cfu/mL. Put a space before and after the x. The x is lower case.
5.0 x 10^5 cfu/mL
Refer to the figure below and determine cfu/ml bacteria in the sample.
5.0 x 10^5 cfu/ml
Denaturation requires water and denaturation of proteins is the antimicrobial action of alcohol. Which of the following solutions of alcohol is more effective against COVID-19?
70%
How many ATP are generated from complete aerobic cellular respiration of two molecules of glucose in bacteria? Your answer must be numeral with description such as 2 ATP
76 ATP
A pure culture in exponential growth phase has a bacterial condition of 6.4 x 10^8 cells/ml. If the bacterium has a generation time of 1 hour, how long ago was the cell concentration 8.0 x 10^7 cells/ml?
8.0 x 10^7 = 6.4 x 10^8 x 2^n -> n=-3 -> 3= t(hours)
Agar Plate
A Petri dish that contains a solidified culture medium
What is transducing phage?
A bacterial virus carrying bacterial DNA.
Lysogen
A bacterium that carries phage DNA (a prophage) integrated into its genome.
Organelle
A cell structure that performs a specific function
Recombinant
A cell that carries a DNA molecule derived from two different DNA molecules
Mutation
A change in the nucleotide sequence of a cell's DNA that is passed on to daughter cells.
Lysogenic Conversion
A change in the properties of a bacterium, conferred by a prophage
Carcinogen
A chemical or radiation that increases the risk of cancer
Antiviral Medication
A chemical that acts by interfering with the infection cycle of a virus and is used to treat a viral infection; also called an antiviral drug.
Disinfectant
A chemical that destroys many, but not all microbes.
Sterilant
A chemical used to destroy all microorganisms and viruses in a product, rendering it sterile; also called a sporocide
Chemotherapeutic Agent
A chemical used to treat disease.
Virion
A complete virus in its inert non-replicating form; also referred to as a viral particle.
Antibiotic
A compound naturally produced by molds or bacteria that inhibits the growth of or kills other microorganisms.
Chemically Defined Medium
A culture medium composed of exact quantities of pure chemicals; generally used only for specific experiments when nutrients must be precisely controlled.
Complex Medium
A culture medium that contains protein digests, extracts, or other ingredients that vary in their chemical composition
Differential Medium
A culture medium with an ingredient that certain microorganisms change in a recognizable way; used to differentiate microbes based on their metabolic traits.
Batch Culture
A culture system such as a tube, flask, or agar plate in which nutrients are not replenished and wastes are not removed
Chain Terminator
A dideoxynucleotide; when this molecule is incorporated into a growing strand of DNA, no additional nucleotides can be added, so elongation of the strand stops
Antiseptic
A disinfectant nontoxic enough to be used on skin.
Colony
A distinct mass of cells arising from a single cell
Capsule
A distinct, thick gelatinous material that surrounds some microorganisms
Protist
A eukaryotic organism other than a plant, animal, or fungus; may be unicellular or multicellular
Pre-mRNA
A eukaryotic transcript that has not yet had the introns removed
Mold
A filamentous fungus
Rhizobia
A group of Gram-negative nitrogen-fixing bacteria that form symbiotic relationships with leguminous plants such as clover and soybeans
Green Bacteria
A group of anoxygenic phototrophs that are green or brownish in color
Parabasalids
A group of flagellated protozoa that lack mitochondria but have hydrogenosomes
Loboseans
A group of protozoa that have amoeboid body forms and no flagella
Heteroloboseans
A group of protozoa that have amoeboid body forms but also form flagellated cells
Apicomplexans
A group of protozoa that penetrate host cells by means of a structure called an apical complex
Roundworm
A helminth that has a cylindrical, tapered body; a nematode
Flatworm
A helminth with a flat body form; further divided into the tapeworms (cestodes) and the flukes (trematodes)
Dead-End Host
A host from which a parasite typically is not passed to another host, and therefore the parasite cannot complete its life cycle
Peptidoglycan
A macromolecule that provides strength to the cell wall; it is found only in bacteria.
Therapeutic Index
A measure of the relative toxicity of a medication, defined as the ratio of minimum toxic dose to minimum effective dose
Cryo-Electron Microscopy (cryo-EM)
A method of electron microscopy in which specimens are rapidly frozen, lessening damage to the sample
Ultra-High-Temperature (UHT)
A method that uses heat to render a product free of all microorganisms that can grow under normal storage conditions
Prototroph
A microorganism that does not require any organic growth factors.
Auxotroph
A microorganism that requires an organic growth factor.
Ligand
A molecule that specifically binds to a given receptor
Enzyme
A molecule, usually a protein, that functions as a catalyst, speeding up a biological reaction.
Plasmodium
A multinucleated form of a slime mold.
Nonsense Mutation
A mutation That generates a stop codon, resulting in a shortened protein
Base Substitution
A mutation in which the wrong nucleotide has been incorporated
Missense Mutation
A mutation that changes the amino acid encoded by DNA
Silent Mutation
A mutation that does not change the amino acid encoded
Cytoplasmic Membrane
A phospholipid bilayer embedded with proteins that surrounds the cytoplasm and defines the boundary of the cell.
Alga
A photosynthetic protist
R Plasmid
A plasmid that encodes resistance to one or more antimicrobial medications.
Pure Culture
A population descended from a single cell.
DNA Microarray
A probe-based technique used to study gene expression patterns.
DNA Gel Electrophoresis
A procedure used to separate DNA fragments according to their size.
Codon
A series of three nucleotides that code for a specific amino acid.
Alternative Sigma Factor
A sigma factor that recognizes promoters controlling genes needed only in non-routine situations
Colony-Forming Units (CFUs)
A single cell or multiple cells attached to one another that give rise to a single colony
Anaerobe Container
A specialized container that can maintain anaerobic conditions; a chemical reaction in a packet generates those conditions
Capsule Stain
A staining method used to observe capsules
Endospore Stain
A staining method used to observe endospores
Flagella Stain
A staining method used to observe flagella
Organ
A structure composed of different tissues coordinated to perform a specific function
Which of the following is an example of degerming?
A surgeon washes her hands before surgery.
Dideoxy Chain Termination Method
A technique used to determine the nucleotide sequence of a strand of DNA; in the procedure, a small amount of chain terminator (a dideoxynucleotide) is added to an in vitro synthesis reaction
Ames Test
A test that screens for potential carcinogens by measuring the ability of a substance to increase the mutation frequency in a bacterial strain
Efflux Pumps
A transporter that moves molecules out of the cell
Composite Transposons
A transposon composed of one or more genes flanked by insertion sequences
Inducer Exclusion
A type of carbon catabolite repression that prevents a carbon/energy source from being transported into the cell
Multiphoton Microscopy
A type of scanning laser microscopy that is less damaging to cells than confocal
Bacteriophages (Phages)
A virus that infects bacteria
Bacteriophage
A virus that infects bacteria; often shortened to phage
Helminth
A worm; parasitic helminths often have complex life cycles
Helminth
A worm; parasitic helminths often have complex life cycles.
Refer to the figure below. Determine which is the competitive inhibitor (A or B) and support your answer.
A, because it binds in the active site.
On which of the following DNA strands would UV radiation most effect?
AATTAGTTC
What substance is formed when H+ go back inside the membrane through ATP synthase?
ATP
In the light reactions of photosynthesis, the energy from sunlight is transformed into energy in _____________.
ATP and NADH
In the light reactions of photosynthesis, the energy from sunlight is transformed into energy in ___________.
ATP and NADPH
FAD/FADH2
Abbreviation for flavin adenine dinucleotide, an electron carrier
NADP+/NADPH
Abbreviations for the oxidized/ reduced forms of nicotinamide adenine dinucleotide phosphate, an electron carrier
NAD+/NADH
Abbreviations for the oxidized/ reduced forms of nicotinamide adenine dinucleotide, an electron carrier
Dimorphic Fungi
Able to assume two forms, as the yeast and mold forms of pathogenic fungi,
Which change in a gene's DNA sequence would have the least effect on the eventual amino acid sequence produced from it?
Addition/deletion of three consecutive nucleotides
Combination Therapy
Administration of two or more antimicrobial medications simultaneously to prevent growth of mutants that might be resistant to one of the antimicrobials
What is the action of azoles?
Affect cell membrane of fungi
Germicide
Agent that kills microorganisms and inactivates viruses
Intercalating Agents
Agents that insert between base pairs in a DNA double helix
What amino acid is carried by the tRNA illustrated below?
Ala
Lichen is association of ______
Alga and fungus
Which of the following statements describe fungi?
All fungi have cell walls made up of chitin. All fungi are heterotrophs.
Signal Sequence
Amino acid sequence that directs cellular machinery to secrete the polypeptide
What type of metabolite are amino acids and antibiotics?
Amino acids are primary metabolites and antibiotics are secondary metabolites.
Storage Granule
An accumulation of a high-molecular-weight polymer synthesized from a nutrient that a cell has in relative excess
Virus
An acellular infectious agent consisting of nucleic acid surrounded by a protein coat.
Viroid
An acellular infectious agent consisting only of RNA.
Prion
An acellular infectious agent consisting only of protein.
Red Tide
An algal bloom that discolors water due to the abundant growth of dinoflagellates
Antimicrobial Medication
An antibiotic or other chemical that acts by inhibiting or killing microorganisms and is used to treat an infectious disease; also called an antimicrobial drug.
Narrow-Spectrum Antimicrobial
An antimicrobial medication that is effective against a limited range of microorganisms.
Broad-Spectrum Antimicrobial
An antimicrobial medication that is effective against a wide range of microorganisms, often including both Gram-positive and Gram-negative bacteria.
Anaerobic Chamber
An enclosed compartment maintained in an anaerobic environment; a special port is used to add or remove items
Constitutive Enzyme
An enzyme that is constantly synthesized by a cell
Plasmid
An extrachromosomal DNA molecule that replicates independently of the chromosome.
Endospore
An extraordinarily resistant dormant cell produced by some types of bacteria.
Dysbiosis
An imbalance in the normal microbiota; may be caused by taking antimicrobial medications
Coulter Counter
An instrument that counts cells in a suspension as they pass through a narrow channel
Polycistronic
An mRNA molecule that carries the information for more than one gene
Acid-Fast
An organism that retains the primary stain in the acid-fast staining procedure
Arthropod
Animal with an external skeleton and jointed appendages such as an insect or arachnid; may act as a vector in transmitting disease.
In Salmonella, antibiotic A has an MIC of 2 ug/mL and antibiotic B has a MIC of 50 ug/mL. Which antibiotic has the higher degree of activity against Salmonella?
Antibiotic A
Penicillin
Antibiotic that interferes with the synthesis of the peptidoglycan portion of bacterial cell walls
O Antigen
Antigenic polysaccharide portion of lipopolysaccharide, the molecule that makes up the outer layer of the outer membrane of Gram-negative bacteria
Co-Trimoxazole
Antimicrobial medication composed of the synergistic combination of sulfonamide and trimethoprim
Mutagen
Any agent that increases the frequency at which DNA is altered (mutated)
Methanogen
Any of a group of archaea that obtain energy by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor, thereby generating methane
A scientist discovers a new species near coral reefs in Australia. On basic microscopic examination and after conducting a few simple experiments, he finds this single-celled species is photosynthetic, has a cell wall and its internal structures are not bound by membranes. It is likely a/an _______________
Archaea
Below are microorganisms cell wall composition. Which is mismatch?
Archaea - Peptidoglycan
Methanogens
Archaea that obtain energy by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor, thereby generating methane
Which of the following are the sexual spores of Baker's yeast?
Ascospores
Binary Fission
Asexual process of reproduction in which one cell divides to form two daughter cells
Budding
Asexual reproductive technique that involves a pushing out of a part of the parent cell that eventually gives rise to a new daughter cell. A process by which some viruses are released from host cells
Polyribosome
Assembly of multiple ribosomes attached to a single mRNA molecule; also called a polysome
Salmonella his- is a/an (auxtotroph or prototroph) and (has or lacks) a functional gene for histidine synthesis.
Auxtotroph; lacks
Refer to figure below. Which tRNA (A, B, C or D) would occupy the A site of the ribosome?
B
Refer to figure 5. In which phase, E. coli utilizes lactose?
B → C
Figure 6 shows the results in the isolation of mutants (histidine auxotrophs) using replica plating method. Plate 1 is the master plate and the colonies (round blue objects with letters) growing in the plate are from cells that have been exposed to mutagens. Which of the colonies are histidine auxotrophs? Type the letters and separate them by comma such as A, B, C, D. Type a space after each comma.
B, D, G
Arrange the following steps to describe transformation in bacteria. A. Fragment of donor DNA enters competent bacteria. B. Bacteria die, their DNA are degraded and released in the environment. C. Fragment of donor DNA integrates with the recipient bacteria D. Transformants are formed.
B-A-C-D
Which does not refer to the shape of a virus?
Bacillus
Mesophiles
Bacteria that grow most rapidly at temperatures between 20°C and 45°C
Gram-Positive Bacteria
Bacteria that have a cell wall characterized by a thick layer of peptidoglycan; when Gram stained, these cells are purple.
Gram-Negative Bacteria
Bacteria that have a cell wall characterized by a thin layer of peptidoglycan surrounded by an outer membrane; when Gram stained, these cells are pink.
Which of the following are the most resistant living organisms?
Bacterial endospores
Restriction-Modification System
Bacterial system that uses restriction enzymes to defend against invading foreign DNA; modification enzymes methylate the host DNA to protect it
Generalized Transducing Particle
Bacteriophage progeny that contains part of a bacterial genome instead of phage DNA due to an error during packaging
Why are Gram-negative (G-) bacteria more resistant to antimicrobial agents than Gram-positive (G+) bacteria?
Because G- have an outer membrane
Sulfa drugs inhibit synthesis of folic acid from PABA in bacteria. Why do cells in person taking sulfa drugs can still synthesize folic acid?
Because humans do not need PABA to make folic acid.
Why do capnophiles grow in candle jars?
Because in candle jars the concentration of carbon dioxide is high.
Explain why mycobacteria are the most resistant of all other vegetative bacteria.
Because of the presence of mycolic acids.
Why would abnormal prions accumulate and normal (PrPC) does not?
Because prion protein is much more resistant to proteases than the normal cellular protein in the cells so the prion protein will accumulate.
Putting foods in a functioning refrigerator (10 C) inhibits the growth of mesophiles. Why?
Because temperature in the refrigerator is below their minimum requirement.
Which of the following is NOT used as a criterion to classify viruses?
Biochemical characteristics
Bioluminescence
Biological production of light
Which is/are benefited in the relationship between cyanobacterium and fungi?
Both algae and cyanobacterium
Which of the following uses inorganic phosphate ADP to ATP?
Both oxidative level phosphorylation and photophosphorylation.
Which statement is false about photosynthesis in purple bacteria or/and in green bacteria
Both use water as reducing agent
Which statement is false about photosynthesis in purple bacteria or/and in green bacteria?
Both use water as reducing agent.
Which of the following can produce the most ATP?
Breakdown of one glucose to 6CO2 and 6H2O
Pasteurization
Brief heat treatment that reduces the number of spoilage organisms and destroys disease-causing microbes.
A crime lab has collected a very tiny amount of DNA from the fingernails of a rape victim and the lab wanted to increase the amount of DNA to be able to do some tests to help solve the crime. How would the lab do this?
By PCR or polymerase chain reaction
How does the CRISPR system protect host bacteria from bacteriophages?
By blocking the infections of same types of phages
How do spirochetes move?
By corkscrew movement of flagella
Figure 6 shows the results in the isolation of mutants (histidine auxotroph) using replica plating method. Plate 1 is the master plate and the colonies (round subjects with letters) growing in the plate are from the cultures that have been exposed to mutagens. Which of the colonies are histidine auxotrophs?
C & E
Redox is also described as transfer of hydrogen. In the reaction below, What is the reducing agent and oxidizing agent? C6H12O6 + 6O2 + 6H2O
C6H12O6 is the reducing agent and 6O2 is the oxidizing agent
The genetic material of viruses is enclosed by a protein coat called _________
Capsid
A virion is composed of ______.
Capsid with either RNA or DNA
Which glycocalyx is firmly attached to the cell surface?
Capsule only
__________ reaction releases ATP and __________ of molecules.
Catabolic, breakdown
Selective Toxicity
Causing greater harm to a pathogen than to the hos
Pili
Cell surface structures that allow cells to adhere to certain surfaces; some types are involved in a mechanism of DNA transfer.
Eukaryotic Cell
Cell type characterized by a membrane-bound nucleus.
Prokaryotic Cell
Cell type characterized by the lack of a membrane-bound nucleus.
RNA Interference (RNAi)
Cellular mechanism that targets specific mRNA molecules for destruction by using small RNA fragments to identify it
Biosynthesis
Cellular processes that synthesize and assemble the subunits of macromolecules, using the energy of ATP
Enterics
Characteristic structures of motility in spirochetes,
Terminal Electron Acceptor
Chemical that is ultimately reduced as a consequence of fermentation or respiration.
High-Level Disinfectant
Chemical used to destroy all viruses and vegetative cells, but not endospores
Of the four groups of fungi, which form flagellated asexual and sexual spores?
Chytridiomycetes
Plaque
Clear area in a monolayer of cells.
What are the two genera of bacteria that form endospores?
Clostridium and Bacillus
Turbidity
Cloudiness in a liquid
Hemagglutination
Clumping of red blood cells
Genetic Code
Code that correlates a codon (set of three nucleotides) to one amino acid
Start Codon
Codon at which translation is initiated; in prokaryotes, typically the first AUG after a ribosome-binding site
Stop Codon
Codon that does not code for an amino acid and is not recognized by a tRNA; signals the end of the polypeptide chain
DNA Library
Collection of cloned molecules that together encompass the entire genome of an organism of interest; each clone can be viewed as one "book" of the total genetic information of the organism of interest
Genome
Complete set of genetic information in a cell or a virus.
Which is the correct order in the direction of the flow of electrons donated by NADH?
Complex I - Ubiquinone - Complex III - Complex IV - O2
SOS Repair
Complex, inducible repair process used to repair highly damaged DNA
Sigma (σ) Factor
Component of RNA polymerase that recognizes and binds to promoters
Intermediate Filament
Component of the eukaryotic cell cytoskeleton
Base Analogs
Compound that structurally resembles a nucleobase closely enough to be incorporated into a nucleotide in place of the natural nucleobase
Disinfection By-Products (DBPs)
Compounds formed when chlorine or other disinfectants react with naturally occurring chemicals in water
Primary Metabolites
Compounds synthesized by a cell during the log phase
Growth Factors
Compounds that a particular bacterium requires in a growth medium because it cannot synthesize them
Reducing Agents
Compounds that readily donate electrons to another compound, thereby reducing the other compound
Some protozoa divide sexually by _____.
Conjugation
The horizontal gene transfer that requires cell-to-cell contact is ______.
Conjugation
Why does conjugation between an Hfr strain and an F- strain not result in two Hfr strains?
Conjugation is typically disrupted before the full copy of fertility factor can be transferred.
The first step in bacterial conjugation is ______.
Contact between the two cells
Cytoplasm
Contents of a cell, excluding the nucleus
Tissue
Cooperative associations of cells in a multicellular organism
Cell Culture (Tissue Culture)
Cultivation of animal or plant cells in the laboratory
Selective Medium
Culture medium that inhibits the growth of certain microorganisms and therefore favors the growth of desired microorganisms
Enrichment Culture
Culture method that provides conditions to enhance the growth of one particular species in a mixed population
Spirillum
Curved rod long enough to form spirals
Tricarboxylic Acid Cycle (TCA Cycle).
Cyclic metabolic pathway that incorporates acetyl-CoA, ultimately generating ATP (or GTP), CO2, and reducing power, also called the Krebs cycle and the citric acid cycle
Bacillus
Cylindrical-shaped bacterium; also referred to as a rod
Actin Filaments
Cytoskeletal structures of eukaryotic cells that allow movement within the cell
Microtubules
Cytoskeleton structures of a eukaryotic cell that form mitotic spindles, cilia, and flagella; long hollow cylinders composed of tubulin
The liquid portion of the cytoplasm is called ____
Cytosol
WOF tRNA (A to H) have occupied the E-site of the ribosome?
D
The procedure used to identify individuals by their genetic sequences is known as _______.
DNA fingerprinting
The procedure used to identify individuals by their unique genetic sequences is known as ________
DNA fingerprinting
A tool of rDNA technology that involves fixing single-strand DNA molecules on a glass slide or nylon membrane is ______.
DNA microarrays
Recombinant DNA Molecule
DNA molecule created by joining DNA fragments from two different sources.
Vector
DNA molecule, often a plasmid, that functions as a carrier of cloned DNA.
cDNA
DNA obtained by using reverse transcriptase to synthesize DNA from an RNA template in vitro; lacks introns that characterize eukaryotic DNA
Non-Homologous Recombination
DNA recombination that does not require extensive nucleotide sequence similarity in the stretches that recombine.
Core Genome
DNA sequences found in all strains of a particular species
Mobile Gene Pool
DNA sequences found in only some strains of a given species; includes plasmids, transposons, phages, and genomic islands
Horizontal Gene Transfer
DNA transfer from one bacterium to another by conjugation, DNAmediated transformation, or transduction.
If Gram-negative bacteria produced proteins that cause changes in porin proteins of their outer membrane, what type of mechanism of resistance to antimicrobial medication is it?
Decreased uptake of the medication
Plasmolysis
Dehydration and shrinkage of cytoplasm from the cell wall as a result of water diffusing out of a cell
Which of the following describes rDNA technology?
Deliberate modification of the genome of an organism for practical purpose
Genetic Engineering
Deliberately altering an organism's genetic information using in vitro techniques.
Boiling kills microorganisms by ____.
Denaturation of proteins
What mechanism to acquire and retain nutrients is present in bioluminescent bacteria?
Derive nutrients from others
Exergonic
Describes a chemical reaction that releases energy because the starting compounds have more free energy than the products
Antiparallel
Describes opposing orientations of the two strands of DNA in the double helix
Synergistic
Describes the acting together of agents to produce an effect greater than the sum of the effects of the individual agents
Bioinformatics
Developing and using computer technology to store, retrieve, and analyze nucleotide sequence data,
Chemostat
Device used to grow bacteria in the laboratory that allows nutrients to be added and waste products to be removed continuously
Parasitic worms, even meters-long tapeworms, are studied in microbiology because______.
Diagnosis usually involves microscopic examination of patient samples.
Differentiate diffusion from facilitated diffusion.
Diffusion does not need transport protein while facilitated diffusion needs transport protein.
A student is going to isolate penicillin resistant bacteria from a soil sample. So, the student prepares a soil suspension and spread the suspension in nutrient agar plates added with penicillin. The method used by the student to isolate mutants is (direct / indirect) selection of mutants.
Direct
Origin of Replication
Distinct region of a DNA molecule at which replication is initiated
Peritrichous Flagella
Distribution of flagella all around a cell
F+ cell
Donor bacterial cell in conjugation, transfers the F plasmid
Cyst
Dormant resting protozoan cell characterized by a thickened cell wall
Cyst
Dormant resting protozoan cell characterized by a thickened cell wall\
DNA Replication
Duplication of a DNA molecule.
What is (are) harmed in the relationship between Bdellovibrio sp. And E.coli?
E. coli only
Reaction-Center Pigments
Electron donors in the photosynthetic process; an example is chlorophyll a
Which of the following processes produce the most ATP from one molecule of glucose?
Electron transport system
Which of the following is used to insert DNA into cells.
Electroporation
What is the other name of lipid A?
Endotoxin
Active Transport
Energy-consuming process by which cells move molecules across a membrane and against a concentration gradient
Which of the following are the most susceptible to disinfectants or antiseptics?
Enveloped viruses
Describe the release of enveloped viruses and non-enveloped viruses from their host cells.
Enveloped viruses are released by budding and non-enveloped viruses are released after the host cell dies.
Inducible Enzyme
Enzyme synthesized only under certain environmental conditions
Catalase
Enzyme that breaks down hydrogen peroxide (H2O2) to produce water (H2O) and oxygen gas (O2)
β-Lactamase
Enzyme that breaks the b-lactam ring of a b-lactam antibiotic, thereby inactivating the medication
Superoxide Dismutase
Enzyme that degrades superoxide to produce hydrogen peroxide
Lysozyme
Enzyme that degrades the peptidoglycan layer of the bacterial cell wall
DNA Ligase
Enzyme that forms covalent bonds between adjacent fragments of DNA
DNA Gyrase
Enzyme that helps relieve the tension in DNA caused by the unwinding of the two strands of the DNA helix during DNA replication
DNA Polymerase
Enzyme that synthesizes DNA, using an existing strand as a template to make a new complementary strand.
RNA Polymerase
Enzyme that synthesizes RNA using one strand of DNA as a template
Primase
Enzyme that synthesizes small fragments of RNA to serve as primers for DNA synthesis during DNA replication
Helicase
Enzyme that unwinds the DNA near the replication fork
Repressible Enzyme
Enzyme whose synthesis can be turned off by certain conditions
DNA Polymerases
Enzymes that synthesize DNA; they use one strand as a template to make the complementary strand
Which of the following chemical agents is used to sterilize medical devices?
Ethylene oxide gas
Fastidious
Exacting; refers to organisms that require growth factors
Hypersensitivity
Exaggerated immune response that damages tissue
Drug-resistant populations of microbes arise when _______.
Exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells.
Plasmid
Extrachromosomal DNA molecule that replicates independently of the chromosome.
Which of the following transport processes move molecules down their electrochemical gradient through carrier or channel proteins?
Facilitated transport
Immersion Oil placed in between the glass slide and objective lens prevents refraction of light decreasing numerical aperture, thereby increasing resolution.
False
Immersion oil placed in between the glass slide and objective lens prevents refraction of light decreasing numerical aperture, thereby increasing resolution.
False
Surgical instruments contaminated with prions are sterilized by autoclaving.
False
Which statement best explains why more ATP is made per molecule of NADH than per molecule of FADH2?
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor
Depth Filter
Filter with complex passages that allow fluid to pass through while retaining microbes
What is the function of the oxygen in aerobic cell respiration?
Final electron acceptor
In feedback inhibition, the inhibitor of the biochemical pathway is the __________.
Final or end product
Phase of Prolonged Decline
Final stage of the growth curve; most cells die during this phase, but a few are able to grow
Primary Stain
First dye applied in a multistep differential staining procedures; generally stains all cells
Penicillin was discovered by ______.
Fleming
Zooplankton
Floating and swimming small animals and protozoa found in marine environments, usually in association with the phytoplankton
Electromagnetic Radiation
Form of energy that travels in waves and has no mass; examples include visible and UV light rays and X rays
Wild Type
Form of the cell or gene as it typically occurs in nature.
Transcript
Fragment of RNA, synthesized using one of the two strands of DNA as a template
Commercially Sterile
Free of all microorganisms capable of growing under normal storage conditions; the endospores of some thermophiles may remain
Sterile
Free of all viable microbes, including endospores and viruses.
Determine the color of the cells in Gram-positive (G+) and Gram-negative (G-) bacteria after the application of the Gram stains?
G+ are purple and G- are red.
Determine the color of the cells in Gram-positive (G+) bacteria and Gram-negative (G-) bacteria after a successful Gram staining?
G+ are purple and G- are red.
What bacteria (G+ or G-) are favored to grow in MacConkey agar (MAC)? What type of culture medium is MAC based on function?
G- ; both selective and differential culture medium
Below are Gram-positive bacteria (G+) or Gram-negative bacteria (G-) and their color after the application of Gram stains. Which is mismatched?
G- after adding the decolorizer -> purple
If a scientist wanted to find DNA fragments of a particular size in a sample, the best technique would be ______.
Gel electrophoresis
The insertion of foreign DNA directly into a cell's nucleus using an instrument to propel a tungsten or gold bead coated with DNA is called _______.
Gene gun
The application of rDNA technology involves locating genes on nucleic acid molecule , frequently by using DNA probes to identify restriction fragments (restriction fragmentation) or clones containing the gene of interest.
Gene mapping
Selectable Marker
Gene that encodes a selectable phenotype such as antibiotic resistance
It is an application of rDNA technology that involves replacing a patient's defective gene with a fragment containing a functional gene.
Gene therapy
Oncogene
Gene whose activity is involved in turning a normal cell into a cancer cell
Microbe
General term encompassing microorganisms and acellular infectious agents such as viruses
Replicase
General term for any virally encoded-encoded enzyme that replicates the genome of an RNA virus
Central Metabolic Pathways
Glycolysis, the TCA cycle, and the pentose phosphate pathway; the transition step is often considered a part of the TCA cycle
Myxobacteria
Gram-negative bacteria that group together to form complex multicellular structures called fruiting bodies.
Prosthecate Bacteria
Gram-negative bacteria that have extensions projecting from the cells, thereby increasing their surface area.
Sulfur-Oxidizing Bacteria
Gram-negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, generating sulfuric acid.
Nitrifiers
Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite.
Cyanobacteria
Gram-negative oxygenic phototrophs; genetically related to chloroplasts.
Lactic-Acid Bacteria
Gram-positive bacteria that generate lactic acid as a major end product of their fermentative metabolism.
Teichoic Acids
Gram-positive cell wall component, composed of chains of a common subunit, either ribitolphosphate or glycerol-phosphate, to which various sugars and D-alanine are usually attached
Coryneforms (Diphtheroids)
Gram-positive cells that are club-shaped and arranged to form V shapes and palisades; resembles the typical microscopic morphology of Corynebacterium species
Sulfa Drugs
Group of antimicrobial medications that inhibit folic acid synthesis
β-Lactam Antibiotics
Group of antimicrobial medications that inhibit peptidoglycan synthesis and have a shared chemical structure called a b-lactam ring
Transmissible Spongiform Encephalopathies (TSEs)
Group of fatal neurodegenerative diseases in which brain tissue develops sponge-like holes
Operon
Group of linked genes whose expression is controlled as a single unit
Electron Transport Chain (ETC)
Group of membrane-embedded electron carriers that pass electrons from one to another, and, in the process, create a proton motive force.
Electron Transport Chain
Group of membrane-embedded electron carriers that pass electrons from one to another, and, in the process, move protons across the membrane to create a proton motive force
Species
Group of related isolates or strains; the lowest basic unit of taxonomy
Growth Curve
Growth pattern observed when cells are grown in a closed system; consists of five stages—lag phase, log phase (or exponential phase), stationary phase, death phase, and the phase of prolonged decline
Reactive Oxygen Species (ROS)
Harmful derivatives of O2 such as superoxide (O2 - ) and hydrogen peroxideterm-430 (H2O2) that are highly toxic to cells
They are specialized hyphae used by parasitic fungi to derive nutrients from other living organisms.
Haustoria or Haustorium
Some scientists were skeptical of Pasteur's results disproving spontaneous generation theory because they could not reproduce the results . How did John Tyndall help explain the conflicting idea?
He demonstrated that some broths require greater boiling times because they contained heat-resistant bacteria forms
Some scientists were skeptical of Pasteur's results disproving spontaneous generation theory because they could not reproduce the results. How did John Tyndall help explain the conflicting idea?
He demonstrated that some broths require greater boiling times because they contained heat-resistant bacterial forms.
Application of ________ in acid-fast staining facilities the uptake of the primary stain by AF+ bacteria.
Heat
What facilitates the entry of malachite green and carbolfuchsin into the cells when doing endospore staining and acid-fast staining?
Heat
Taq Polymerase
Heat-stable DNA polymerase of the thermophilic bacterium Thermus aquaticus
Fungus
Heterotrophic eukaryotic organism containing chitin in the cell wall
Fungus
Heterotrophic eukaryotic organism with a chitinous cell wall.
Protozoa
Heterotrophic protists
Protozoa
Heterotrophic protists.
________ cell refers to a cell in which the F plasmid has been integrated into the cell chromosome. It is a three-letter word answer.
Hfr
______ cell refers to a cell in which the F plasmid has been integrated into the cell chromosome.
Hfr or high frequency recombination
Bacterial plasma membrane does not have cholesterol, instead some have __________ to help maintain the stability of the membrane.
Hopanoids
Cell A and Cell B are totally unrelated, but Cell A receives DNA from Cell B and incorporates DNA into its chromosome. This type of gene transfer is ______.
Horizontal gene transfer
Fungi cause human illness in three ways. If the fungus causes an allergic reaction to the person, what general way is it?
Hypersensitivity reaction
Acute Infection
Illness characterized by signs and symptoms that develop quickly but last a relatively short time
Which of the following is an example of xenotransplant?
Implanting pig heart valves into a human heart
Complementary
In DNA structure, the nucleobases that characteristically hydrogen bond to one another; A (adenine) is complementary to T (thymine), and G (guanine) is complementary to C (cytosine)
Replication Fork
In DNA synthesis, the site at which the double helix is being unwound to expose the single strands that can function as templates
Lag Phase
In a bacterial growth curve, stage characterized by extensive macromolecule and ATP synthesis but no increase in cell number
Death Phase
In a bacterial growth curve, stage in which the number of viable cells decreases at an exponential rate
Stationary Phase
In a bacterial growth curve, stage in which the number of viable cells remains constant
Decolorizing Agent
In a differential staining procedure, the chemical used to remove the primary stain
Counterstain
In a differential staining procedure, the stain applied to give a contrasting color to bacteria that do not retain the primary stain
Explain how bacteria maintain their near-neutral internal pH when exposed to an acidic or basic environment?
In acidic environments, bacteria pump out H+ and in basic environment, bacteria bring in H+.
Antagonistic
In antimicrobial therapy, a combination of antimicrobial medications in which the action of one interferes with the action of the other
Capped
In eukaryotic gene expression, adding a methylated guanine derivative to the 59 end of the mRNA
Polyadenylation
In eukaryotic gene expression, adding a series of adenine derivatives to the 3' end of an mRNA transcript
Activator
In gene regulation, a protein that enhances the ability of RNA polymerase to initiate transcription
Competent
In horizontal gene transfer, physiological condition in which a bacterial cell is capable of taking up DNA
Indirect Selection
In microbial genetics, a technique for isolating mutants and identifying organisms unable to grow on a medium on which the parents do grow; often involves replica plating
Vector
In molecular biology, a piece of DNA that acts as a carrier of a cloned fragment of DNA. In epidemiology, any living organism that can carry a disease-causing microbe; most commonly arthropods such as mosquitoes and ticks.
Fruiting Body
In myxobacteria, a complex aggregate of cells, visible to the naked eye, produced when nutrients or water are depleted. In fungi, a specialized spore-producing structure.
Outer Membrane
In prokaryotic cells, the unique lipid bilayer of Gram-negative cells that surrounds the peptidoglycan layer. In eukaryotic cells, the membrane on the cytoplasmic side of organelles that have double membranes
Theory
In science, an explanation supported by an extensive amount of experimental evidence
Quantal Assay
In virology, a method that uses several dilutions of a virus culture administered to appropriate hosts to determine virus titer
Polymerase Chain Reaction (PCR)
In vitro technique used to repeatedly duplicate (amplify) a specific region of a DNA molecule, increasing the number of copies exponentially.
Which of the following is used to sterilize inoculating wire loops?
Incineration
Refer to the figure below. Why there is an increasing rate of reaction when temperature is increased from 0oC to 40oC?
Increasing the temperature causes more effective collision between enzyme and substrate.
In lambda phage replication, what is a lysogen?
Infected host cell
Lysogenic Infection
Infection by a temperate phage that results in a prophage residing in the host
Persistent Infection
Infection in which the causative agent remains in the body for long periods of time, often without causing symptoms of disease
Healthcare-Associated Infections (HAIs)
Infections acquired while receiving treatment in a hospital or other healthcare facility
Chronic Infections
Infections that develop slowly and persist for months or years
Preservation
Inhibition of microbial growth to delay spoilage.
Bacteriostatic
Inhibits the growth of bacteria.
Activation Energy
Initial energy required to break a chemical bond
Chemolithotrophs use ___________ as their sources of energy. For example, hydrogen bacteria can use __________ as their source of energy
Inorganic compounds, H2
When cells are placed in hypotonic solution, water moves (outside or inside) the cell because the concentration of solutes is (higher or lower) than the concentration of solution inside the cell.
Inside; Lower
Flow Cytometer
Instrument that counts cells in a suspension by measuring the scattering of light by individual cells as they pass by a laser
All of the following microbial control methods are microbiostatic EXCEPT _______.
Ionizing radiation
Which of the following drugs synthesis of mycolic acids?
Isoniazid
How does M13 phage genome enter the host cell like E.coli?
It attaches to protein on F pilus.
How does the M13 phage genome enter the host cell like E. coli?
It attaches to protein on F pilus.
What is the mode of action of lysozyme in bacterial cell wall?
It breaks the bonds linking the amino sugars in the glycan chain.
All are true about Kreb's cycle except _________.
It consists of 10 stages and occurs in the mitochondria in eukaryotes
Describe the structure and composition of plasma membrane according to the fluid mosaic model.
It is composed of two layers phospholipids and mosaic of proteins.
Which of the following describes photosynthesis by photoheterotrophs?
It uses hydrogen sulfide as a source of electrons.
Who showed that flasks containing broth made from plant or animal gave rise to microorganisms even though the broth was heated and the flask was sealed with cork?
John T. Needham
Bactericidal
Kills bacteria
Fungicide
Kills fungi; used to describe the effects of some antimicrobial chemicals
What type of protozoa have at least one flagellum and a distinctive complex mass of DNA in their large single mitochondrion made of interlocking rings?
Kinetoplastids
Tissue Culture
Laboratory culture of plant or animal cells
Anoxic
Lacking O2
In the lac operon, the presence of ________ cause the release of the repressor protein from the DNA, facilitating transcription.
Lactose
The (lagging or leading) strand of the replicating DNA synthesizes Okazaki fragments.
Lagging
Genomic Island
Large segment of DNA acquired from another species through horizontal gene transfer; an example is a pathogenicity island
Prophage
Latent form of a temperate phage whose DNA has been inserted into the host's DNA
Provirus
Latent form of a virus in which the viral DNA is incorporated into the chromosome of the host
In this animal virus infection, the viral genome (provirus) remains silent in the host cell but can reactivate.
Latent infections
A set of clones representing the entire genome of an organism is known as a gene _____.
Library
What enzyme joins the gene of interest and plasmid together?
Ligase
Endotoxin
Lipopolysaccharide, a component of the outer membrane of Gram-negative cells that can cause symptoms such as fever and shock; lipid A is responsible for the effects of endotoxin
Which type of protozoa have ameboid (flexible) body form?
Loboseans and heteroloboseans
Suzy wants to determine the antimicrobial ability of her body wash to Staphylococcus epidermis. Suzy then, asks you what phase in the growth curve of S. epidermis she will use. What will you advise and why?
Log phase because the cells are active and are sensitive to the antibacterial agent in the body wash.
Spirochetes
Long helical bacteria that have flexible cell walls and endoflagella.
When mature T4 phages are released from the host cell, what enzyme digest the cell wall?
Lysozyme
A phage that replicates inside the host cell and then lyses its host during its release is what type of phage?
Lytic phage
A certain antibiotic was tested for its efficiency. Different concentrations of the antibiotic were prepared in broth tubes and then the tubes were inoculated with the test bacterium. Growth of the test bacterium was observed after 24 hours. Then 0.1 mL from the 24 hour broth tubes was placed in nutrient agar and the agar plates were incubated for another 24 hour. Determine the MIC and MBC from figure 9.
MIC is 4 ug/mL and MBC is 10 ug/mL
Mushroom
Macroscopic reproductive structures formed by some types of fungi
Antigenic Shift
Major change in a viral surface antigen that renders antibodies made against the previous version ineffective
Selectively Permeable
Material that allows only certain molecules to pass through freely
CRISPR System
Mechanism by which bacterial cells maintain a historical record of phage infections, and thereby become immune to subsequent infections by the same phages; the system also protects against other types of foreign DNA
Excision Repair
Mechanism of DNA repair in which a fragment of single-stranded DNA that contains mismatched bases is removed and replaced
Two-Component Regulatory System
Mechanism of gene regulation that uses a sensor and a response regulator
Transduction
Mechanism of horizontal gene transfer in which bacterial DNA is transferred inside a phage coat.
DNA-Mediated Transformation
Mechanism of horizontal gene transfer in which the bacterial DNA is transferred as "naked" DNA.
Conjugation
Mechanism of horizontal gene transfer in which the donor cell physically contacts the recipient cell.
Transport Systems
Mechanisms used to transport nutrients and other small molecules across the cytoplasmic membrane.
The application of rDNA technology has largely replaced traditional identification techniques. This involves examining a patient specimens for sequences unique to certain pathogens.
Medical diagnosis
Non-Critical Instruments
Medical instruments and surfaces such as stethoscopes and countertops that only come into contact with unbroken skin
Semicritical Instruments
Medical instruments such as endoscopes that come into contact with mucous membranes, but do not penetrate body tissues
Critical Instruments
Medical instruments such as needles and scalpels that come into direct contact with body tissue
Carbapenem-Resistant Enterobacteriaceae (CRE)
Members of the Enterobacteriaceae that are resistant to carbapenems, as well as nearly all other antimicrobial medications
Nucleus
Membrane-bound organelle in a eukaryotic cell that contains chromosomes and the nucleolus
Lysosomes
Membrane-bound structure in eukaryotic cells that contains powerful degradative enzymes
Endolysosome
Membrane-bound vacuole formed when an endosome fuses with a lysosome
Precursor Metabolites
Metabolic intermediates that can be either used to make the subunits of macromolecules or oxidized to generate ATP.
Glycolysis
Metabolic pathway that oxidizes glucose to pyruvate, generating ATP and reducing power
Pentose Phosphate Pathway
Metabolic pathway that starts the degradation of glucose, generating reducing power in the form of NADPH, and two precursor metabolites
Calvin Cycle
Metabolic pathway used by many autotrophs to incorporate CO2 into an organic form; also called the Calvin-Benson cycle
Anaerobic Respiration
Metabolic process in which electrons are transferred from the electron transport chain to a terminal electron acceptor other than O2
Aerobic Respiration
Metabolic process in which electrons are transferred from the electron transport chain to molecular oxygen (O2)
Fermentation
Metabolic process that stops short of oxidizing glucose or other organic compounds completely, using an organic intermediate as a terminal electron acceptor.
Respiration
Metabolic process that transfers electrons stripped from a chemical energy source to an electron transport chain, generating a proton motive force that is then used to synthesize ATP.
Secondary Metabolites
Metabolic products synthesized during late-log and stationary phase
Penicillin Enrichment
Method for increasing the relative proportion of auxotrophic mutants in a population by using penicillin to kill growing prototrophic cells
Pour-Plate Method
Method of inoculating an agar medium with bacterial cells; the inoculum and melted agar are added to a Petri dish, where the agar hardens; the colonies grow both on the surface and within the medium
Wet Mount
Method of observing a living organisms in a drop of liquid using a microscope
Plate Count
Method to measure the concentration of viable cells by counting the number of colonies that develop from a sample added to an agar plate.
Plaque Assay
Method used to measure the number of viral particles present in a sample.
Recombinant DNA Techniques
Methods used to join DNA from two different sources in vitro
Which microbes are responsible for spoilage of acidic foods?
Microbes that can grow at high concentration of H+
When nutrient is low, Myxobacter sp forms a resting body called ______
Microcyst
Psychrophile
Microorganism that grows best between -5°C and 15°C
Penicillins are effective against what group of microorganisms?
Microorganisms with cell wall made up of peptidoglycan.
Phytoplankton
Microscopic free-floating photosynthetic organisms.
Inclusion Body
Microscopically visible structure within a virally infected cell, representing the site at which the virus replicates
A mutation that results in changing a codon such that a different amino acid is specified is called ______ mutation.
Missense mutation
Fluid Mosaic Model
Model that describes the dynamic nature of the cytoplasmic membrane
Adenosine Diphosphate (ADP)
Molecule that accepts an inorganic phosphate (Pi) generating ATP
Corepressor
Molecule that binds to an inactive repressor, thereby allowing it to function as a repressor
Lipopolysaccharide (LPS)
Molecule that makes up the outer layer of the outer membrane of Gram-negative bacteria.
Electron Carriers
Molecules cells use to shuttle electrons; they readily accept and then donate electrons
High-Temperature-Short-Time (HTST) Method
Most common pasteurization protocol; using this method, milk is pasteurized by holding it at 72°C for 15 seconds
Simple Diffusion
Movement of solutes from a region of high concentration to one of low concentration; does not involve transport proteins
Point Mutation
Mutation in which only a single base pair is involved
Frameshift Mutation
Mutation resulting from the addition or deletion of a number of nucleotides not divisible by three
Spontaneous Mutation
Mutation that occurs naturally during the course of normal cell processes
Induced Mutations
Mutation that results from the organism being treated with an agent that alters its DNA
What is the symbiotic relationship between bioluminescent bacteria and squid or fish?
Mutualism
What is the symbiotic relationship between the organisms with mycorrhiza?
Mutualism
What is the waxy substance present only in acid fast positive bacteria and absent in acid fast negative bacteria?
Mycolic acid
All of the following are obligate intracellular parasites except ________.
Mycoplasma
Which of the following is the brain-eating amoeba?
Naegleria fowleri
Which type of staining is suitable to color bacterial capsules?
Negative Staining
The conversion of ammonium up to nitrate is accomplished by ______.
Nitrosomonas alone
Will heating destroy the structure of viroids?
No, because viroids are single-stranded RNA.
Water Molds
Non-photosynthetic type of organism that forms masses of white threads on decaying material; similar to the fungi but not related genetically
Cofactor
Non-protein component required for the activity of some enzymes
Coenzyme
Non-protein organic compound that assists some enzymes, acting as a loosely bound carrier of small molecules or electrons
Below are acid fast positive bacteria (AF+) or acid fast negative bacteria (AF-) and their color after the application of acid fast stains. Which is mismatched?
None is mismatched
All are beneficial effects of microorganisms except ________
None, all are beneficial effects of microorganisms
Cookies have a water activity of 0.3. Can normal bacteria grow on this food? Support your answer.
Normal bacteria cannot grow on this food because the water activity is too low to support their metabolism.
Mitosis
Nuclear division process in eukaryotic cells that ensures the daughter cells receive the same number of chromosomes as the original parent
Okazaki Fragments
Nucleic acid fragment synthesized as a result of the discontinuous replication of the lagging strand of DNA
Semiconservative Replication
Nucleic acid replication that results in each of the two double-stranded molecules containing one of the original strands (the template strand) and one newly synthesized strand
Activator-Binding Site
Nucleotide sequence that precedes an ineffective promoter
Promoter
Nucleotide sequence to which RNA polymerase binds to start transcription.
Dideoxynucleotide (ddNTP)
Nucleotide that lacks the 39OH group, the portion required for the addition of subsequent nucleotides during DNA synthesis
In animal host cells, the genome of DNA viruses are mostly replicated in the _____ and genome of RNA viruses are replicated in the _______.
Nucleus ; cytoplasm
Burst Size
Number of newly formed virus particles released when the infected host cell lyses
Limiting Nutrient
Nutrient that limits growth because it is present at the lowest concentration relative to need
Redox is also described as transfer of hydrogen. In the reaction below. What substance is reduced? C6H12O6 + 6O2 -> 6CO2 + 6H2O
O2
What is/are the final electron acceptor/s of nitrifiers?
O2 only
What is meant by the description "antiparallel" regarding the strands that make up DNA?
One strand runs in 5' to 3' direction and the other strand runs 3' to 5' direction.
lac Operon
Operon that encodes the proteins required for the degradation of lactose; it serves as one of the most important models for studying gene regulation
Mitochondrion
Organelle in eukaryotic cells in which the majority of ATP synthesis occurs
Endoplasmic Reticulum
Organelle of eukaryotes where macromolecules destined for the external environment of other organelles are synthesized
Smooth Endoplasmic Reticulum
Organelle of eukaryotic cells that is the site of lipid synthesis and degradation and calcium ion storage
Peroxisome
Organelle that uses hydrogen peroxide and superoxide to degrade substances
Rough Endoplasmic Reticulum
Organelle where proteins destined for locations other than the cytoplasm are synthesized
Chloroplasts
Organelles in photosynthetic eukaryotic cells that harvest the energy of sunlight and use it to synthesize ATP, which is then used to fuel the synthesis of organic compounds
Eukaryote
Organism composed of one or more eukaryotic cells; members of the domain Eukarya are eukaryotes.
Intermediate Host
Organism in which asexual reproduction or an immature form of a parasite occurs.
Definitive Host
Organism in which sexual reproduction or the adult form of a parasite occurs.
Halotolerant
Organism that can grow in relatively high salt concentrations, up to 10% NaCl
Aerotolerant Anaerobes
Organism that can grow in the presence of O2 but never uses it as a terminal electron acceptor; an obligate fermenter
Obligate Anaerobe
Organism that cannot multiply, and is often killed, in the presence of O 2 .
Facultative Anaerobe
Organism that grows best if O 2 is available, but can also grow without it.
Heterotroph
Organism that obtains carbon from an organic compound such as glucose
Halophile
Organism that prefers or requires a high salt (NaCl) medium to grow
Obligate Aerobe
Organism that requires O 2 .
Saprophyte
Organism that takes in nutrients from dead and decaying matter
Autotroph
Organism that uses CO2 as its main carbon source
Thermophile
Organism with an optimum growth temperature between 45°C and 70°C
Neutrophiles
Organisms that can live and multiply within the range of pH 5 (acidic) to pH 8 (basic) and have a pH optimum near neutral (pH 7)
Primary Producer
Organisms that convert CO2 into organic compounds; by doing so, they sustain other life forms, including humans
Obligate Intracellular Parasites
Organisms that grow only inside living cells
Alkaliphiles
Organisms that grow optimally at a pH above 8.5
Acidophiles
Organisms that grow optimally at a pH below 5.5
Chemolithotrophs
Organisms that harvest energy by oxidizing inorganic chemicals.
Chemoorganotrophs
Organisms that harvest energy by oxidizing organic chemicals.
Hyperthermophiles
Organisms that have an optimum growth temperature between 70°C and 110°C
Extremophiles
Organisms that live under extremes of temperature, pH, or other environmental conditions
Chemotrophs
Organisms that obtain energy by oxidizing chemical compounds
Chemoorganotrophs
Organisms that obtain energy by oxidizing organic compounds such as glucose; in general, chemoorganotrophs are chemoorganoheterotrophs
Microaerophiles
Organisms that require small amounts of O2 (2% to 10%) for growth, and are inhibited by higher concentrations
Phototrophs
Organisms that use light as a source of energy
Which requires a higher temperature and longer time to sterilize? Support your answer.
Oven sterilization because penetration of heat is slower due to absence of water.
Analyze the figure and determine which enzyme is not affected by pH?
Papain
Intron
Part of the eukaryotic chromosome that does not code for a protein; removed from the RNA transcript before the mRNA is translated
Which process produces precursor metabolites and NADPH needed to make nucleotides?
Pentose phosphate pathway
If the upper strand of the DNA molecule below acts as template to make mRNA, what is the sequence of amino acids that will be translated from the mRNA? 3' AAG-CAA-GAC-GAA 5' 5' TTC-GTT -CTG-CTT 3'
Phe-Val-Leu-Leu
Which groups of microorganisms use CO2 as carbon source and light as source of energy?
Photoautotrophs
The organisms that use light as a source of energy and glucose as source of carbon are called _____.
Photoheterotrophs
Anoxygenic Phototrophs
Photosynthetic organisms that do not produce O2
Oxygenic Phototrophs
Photosynthetic organisms that produce O2
Accessory Pigments
Photosynthetic pigments such as carotenoids that capture light energy not absorbed by chlorophylls
Algae
Photosynthetic protists.
Replicon
Piece of DNA that is capable of replicating; contains an origin of replication
Antennae Pigments
Pigments of photosynthetic organisms that make up a complex that acts as a funnel, capturing light energy and transferring it to a reaction-center chlorophyll
Which of the following viruses enter their host cells via wounds in cell walls?
Plant viruses
Transgenic
Plants and animals into which new DNA has been introduced by genetic engineering
A clear area against a confluent "lawn" of bacteria is called a _____.
Plaque
Chlorophyll in photosynthetic bacteria is located in the _________.
Plasma membrane
Plasma membrane of thermophiles is stable at higher temperatures and plasma membrane of psychrophiles are stable at lower temperatures. Explain Why?
Plasma membrane of thermophiles has higher content of saturated fatty acids while plasma membrane of psychrophiles has higher content of unsaturated fatty acids.
Plasma membrane of thermophiles is stable at higher temperatures and plasma membrane of psychrophiles is stable at lower temperatures. Explain why?
Plasma membrane of thermophiles has higher content of saturated fatty acids while plasma membrane of psychrophiles has higher content of unsaturated fatty acids.
F Plasmid
Plasmid found in donor cells of Escherichia coli that codes for the F or sex pilus and makes the cell F+
Resistance (R) Plasmid
Plasmid that carries genetic information for resistance to one or more antimicrobial medications and heavy metals
Conjugative Plasmid
Plasmid that carries the genes for a sex pilus and can transfer copies of itself to other bacteria during conjugation
They are extrachromosomal DNA containing genes for antibiotic resistance, heavy metal resistance, sex pilus and others. It is a one-word answer (plural) and spelling matters.
Plasmids
Ergot
Poisonous substance produced by the fungus that causes rye smut
Biofilm
Polymer-encased community of microorganisms.
Which of the following processes is used to "amplify" DNA making large numbers of copies from a small sample?
Polymerase chain reaction
Agar
Polysaccharide extracted from marine algae that is used to solidify microbiological media
Glycocalyx
Polysaccharide layer that surrounds some cells and generally functions as a mechanism of either protection or attachment
Channel
Pore-forming membrane protein that allows specific ions to diffuse into and out of a cell
Aquaporins
Pore-forming membrane proteins that specifically allow water to pass through
Lipid A
Portion of lipopolysaccharide (LPS) that anchors the molecule in the lipid bilayer of the outer membrane of Gram-negative cells; it plays an important role in the body's ability to recognize the presence of invading bacteria, but is also responsible for the toxic effects of LPS
Exons
Portions of eukaryotic genes that will be transcribed and then translated into proteins; interrupted by introns
Basic stain has a ______ charge chromogen and forms an ionic bond with _____ charge part of the cell.
Positively; negatively
Aflatoxin
Potent toxin made by Aspergillus species
Bacteriostatic
Prevents the growth of bacteria, but does not kill them.
An infectious protein is an ______.
Prion
_________ cause several neurodegenerative diseases in humans and animals such as spongiform encephalitis (sponge-like appearance of the brain tissues).
Prions
DNA Cloning
Procedure in which a fragment of DNA is inserted into a vector and then transferred into another cell, where it then replicates.
Kirby-Bauer Disc Diffusion Test
Procedure used to determine if a bacterium is susceptible to concentrations of an antimicrobial medication usually present in the bloodstream of an individual receiving the medication
Aseptic Technique
Procedures that help prevent the accidental introduction of unwanted microbes.
Aseptic Technique
Procedures that help prevent the introduction of unwanted microbes
Homologous Recombination
Process by which a cell replaces a stretch of DNA with a segment that has a similar nucleotide sequence.
Reversion
Process by which a second mutation corrects a defect caused by an earlier mutation
Exocytosis
Process by which eukaryotic cells expel material; membrane-bound vesicles inside the cell fuse with the plasma membrane, releasing their contents to the external medium
Pinocytosis
Process by which eukaryotic cells take in liquid and small particles from the surrounding environment by internalizing and pinching off small pieces of their own membrane, bringing along a small volume of liquid and any material attached to the membrane
Phage Induction
Process by which phage DNA is excised from bacterial chromosomal DNA
Antigenic Variation
Process by which routine changes occur in a microbial surface antigen
Meiosis
Process in eukaryotic cells by which the chromosome number is reduced from diploid (2n) to haploid (1n)
Carbon Fixation
Process of converting inorganic carbon (CO2) to an organic form
DNA Sequencing
Process of determining the nucleotide sequence of a DNA molecule.
Schizogony
Process of multiple fission in which the nucleus divides a number of times before individual daughter cells are produced
Disinfection
Process of reducing or eliminating pathogenic microorganisms or viruses in or on a material so that they are no longer a hazard
Splicing
Process that removes introns from eukaryotic precursor RNA to generate mRNA
Catabolism
Processes that harvest energy released during the breakdown of compounds such as glucose, using it to synthesize ATP.
Anabolism
Processes that synthesize and assemble the subunits of macromolecules, using energy of ATP; biosynthesis.
Mutagens are useful in biotechnology research for _______.
Producing organisms with altered phenotypes.
Apoptosis
Programmed cell death
The extension of cytoplasm and cell wall of Caulobacter sp is called ____.
Prosthecate
Capsid
Protein coat that surrounds the nucleic acid of a virus
Photosystems
Protein complexes within which chlorophyll and other light-gathering pigments are organized; located in special photosynthetic membranes
Cyclic AMP-Activating Protein (CAP)
Protein that binds to cAMP to promote gene transcription
Repressor
Protein that binds to the operator site and prevents transcription
Chaperone
Protein that helps other proteins fold properly
Which of the following microorganisms don't have cell wall?
Protozoa
You isolated a microorganism from the soil and your analysis shows that the microorganism is unicellular, no cell wall and has a nucleus. What could this microorganism be?
Protozoa
WOF microorganisms generates NADP by reverse electron transport?
Purple bacteria
In transcription, what enzyme binds to a specific region of DNA and breaks the hydrogen bonds to begin the process. It is a two-word answer (singular) and spelling matters.
RNA polymerase
Below are enzymes involved in DNA replication and their actions. Which is mismatched?
RNA primase - removes RNA primers
Monocistronic
RNA transcript that carries one gene
When fatty foods are broken down by microorganisms producing fatty acids and glycerol, the type of degradation is __________
Rancidity
F- cell
Recipient bacterial cell in conjugation
Allosteric
Refers to an enzyme or other protein that contains a site to which a small molecule can bind and change the protein's activity
Oxidized
Refers to loss of electrons
Reduced
Refers to the gain of electrons
Zone of Inhibition
Region around a disc where bacteria are unable to grow due to adverse effects of the compound in the disc
Operator
Region located immediately downstream of a promoter to which a repressor can bind; binding of the repressor to the operator prevents RNA polymerase from progressing past that region, thereby blocking transcription
Nucleoid
Region of a prokaryotic cell containing the DNA
Secretion
Releasing a substance from a cell or tissue
Mismatch Repair
Repair mechanism in which an enzyme cuts the DNA near a mismatched nucleobase, resulting in the removal and replacement of a short stretch of nucleotides
Bdellovibrio ______.
Reproduces inside bacterial cells
Acquired Resistance
Resistance that develops due to genetic changes, including mutation and horizontal gene transfer.
When bacteria are protected from infection by bacteriophages by quickly degrading the incoming bacteriophage DNA is what type of bacterial defenses against phages?
Restriction modification system
Figure 11 is an illustration of the structures of common bread mold. Identify the structures that is encircled and pointed by the blue arrow (be specific).
Rhizoids
Coccobacillus
Rod that is so short it can be mistaken for a coccus
Tumbles occur when the flagella_______.
Rotate clockwise
In the Ames test, a chemical is a presumptive mutagen if ______.
S. typhimurium his- will grow in minimal glucose medium because it reverts to S. typhimurium his+
Transposon
Segment of DNA that can move from one site to another in a cell's genome.
Natural Selection
Selection by the environment of those cells best able to grow in that environment
An antibiotic made by microorganisms and modified by chemists in the laboratory is called ______.
Semi-synthetic
An E-strip containing different concentrations of tetracycline was put on the surface of an agar plate swabbed with E.coli. After 24 hours of incubation, the result is shown in figure 10. Using the table next to the results, determine if E.coli is sensitive, intermediate, or resistant to the antibiotic.
Sensitive
Ribosome-Binding Site
Sequence of nucleotides in bacterial mRNA to which a ribosome binds; the first time the codon for methionine (AUG) appears after that site, translation generally starts
Anticodon
Sequence of three nucleotides in a tRNA molecule that is complementary to a codon in mRNA
Golgi Apparatus
Series of membrane-bound flattened sacs within eukaryotic cells that serve as the site where macromolecules synthesized in the endoplasmic reticulum are modified before they are transported to other destinations
Metabolic Pathway
Series of sequential chemical reactions
Regulon
Set of related genes transcribed as separate units but controlled by the same regulatory protein
Sphaerotilus and Leptothrix are examples of ____.
Sheathed bacteria
Insertion Sequence (IS)
Short piece of DNA that has the ability to move from one site on a DNA molecule to another; simplest type of transposable element
Vibrio
Short, curved rods-haped bacterial cell
Fluke
Short, non-segmented, bilaterally symmetrical flatworm
A mutation that changes a codon into a different codon,but both codons specify the same amino acid, thus causing no change in the resulting polypeptide is called ______ mutation.
Silent mutation
Which of the following is an example of sanitization?
Silver wares in a public restaurant are washed in boiling water.
Streak-Plate Method
Simplest and most commonly used technique for isolating bacteria; a series of successive streak patterns is used to sequentially dilute an inoculum on the surface of an agar plate
DNA Probe
Single-stranded piece of DNA, tagged with an identifiable marker, that is used to detect a complementary sequence.
Active Site
Site on an enzyme to which the substrate binds; also known as the catalytic site
Classification of viruses is based on all of the following except ___
Size of virus
Scabies
Skin disease caused by a parasitic mite
Antigenic Drift
Slight changes in a viral surface antigen that render antibodies made against the previous version only partially protective
Cellular Slime Molds
Slime mold with a vegetative form composed of single, amoeba-like cells. When they run out of food, the single cells aggregate into a mass of cells called a slug
Gas Vesicles
Small rigid compartments produced by some aquatic bacteria that provide buoyancy to the cell
High-Efficiency Particulate Air (HEPA) Filters
Special filters that remove from air nearly all particles, including microorganisms, that have a diameter 0.3 μm or larger
Fluorescence Microscope
Special type of microscope used to observe cells that have been stained or tagged with fluorescent dyes
Heterocyst
Specialized non-photosynthetic cells of cyanobacteria within which nitrogen fixation occurs
The protein projections on the surface of an animal virus that are involved in attachment to the host cell are called ______.
Spikes
Exponential (Log) Phase
Stage in the growth curve during which cells divide at a constant rate; generation time is measured during this period of active multiplication.
Gram Stain
Staining technique that divides bacteria into one of two groups, Grampositive or Gram-negative, on the basis of color after staining
Negative Staining
Staining technique that uses an acidic dye to stain the background against which colorless cells can be seen
Most Probable Number (MPN) Method
Statistical estimate of cell numbers; a sample is successively diluted to determine the point at which subsequent dilutions receive no cells
Methicillin-Resistant Staphylococcus aureus (MRSA)
Strains of Staphylococcus aureus that are resistant to methicillin
Template
Strand of nucleic acid that a polymerase uses to synthesize a complementary strand
Arthur was isolating bacteria from a soil suspension. He used an inoculating loop to sequentially spread a loopful of the soil suspension on the surface of a TSA agar plate. What method to obtain well-isolated colonies was Arthur using?
Streak plating
Open Reading Frames (ORFs)
Stretch of DNA, generally longer than 300 base pairs, that has a reading frame beginning with a start codon and ending with a stop codon; the region likely encodes a protein
Pathogenicity Islands
Stretches of DNA in bacteria that code for virulence factors and appear to have been acquired from other bacteria
Ribosome
Structure involved in protein synthesis.
Chromosome
Structure that carries an organism's hereditary information
Ribosome
Structure that facilitates the joining of amino acids during translation; composed of ribosomal RNA (rRNA) and protein.
Spikes
Structures on the outside of the virion that bind to host cell receptors
Genomics
Study and analysis of the nucleotide sequence of DNA
Substrate
Substance on which an enzyme acts to form products. Surface on which an organism will grow.
Inducer
Substance that activates transcription of certain genes
Bactericide
Substance that kills bacteria
Which statement is true about the induce-fit model of enzyme action?
Substrate binds to enzyme and enzyme changes in shape to conform to the shape of the substrate
WOF uses phosphate from organic molecules to phosphorylate ADP to ATP?
Substrate level phosphorylation
Metabolism
Sum total of all the enzymatic chemical reactions in a cell
Lichen
Symbiotic association of a fungus and either a green alga or a cyanobacterium
Mycorrhiza
Symbiotic relationship between certain fungi and the roots of plants
Drugs are more effective when taken together are called ______.
Synergistic
Oxidative Phosphorylation
Synthesis of ATP using the energy of a proton motive force created by harvesting chemical energy.
Photophosphorylation
Synthesis of ATP using the energy of a proton motive force created by harvesting radiant energy.
Substrate-Level Phosphorylation
Synthesis of ATP using the energy released in an exergonic (energy-releasing) chemical reaction during the breakdown of the energy source.
This tool is used by scientists to make probes, which are nucleic acid molecules with a specific nucleotide sequences that have been labeled with radioactive or fluorescent chemicals so that their locations can be detected.
Synthetic nucleic acid
Salmonella typhi has a generation time of 20 minutes. If you start with 10 cells per mL. Approx how many cells are there per mL after 12 hours?
T=12 hours = 270 minutes and g = 20 minutes , so n=t/g = 270/20 = 36 Then , Nt=No x 2^n = 10 x 2^36 = 6.9 x 10^11 cells
Penicillin-Binding Proteins (PBPs)
Target of β-lactam antimicrobial medications; their role in bacteria is peptidoglycan synthesis
Genus
Taxonomic category of related organisms, usually containing several species. The first name of an organism in the Binomial System of Nomenclature
Replica Plating
Technique for the simultaneous transfer of organisms in separated colonies from one medium to another
Direct Selection
Technique of selecting mutants by plating organisms on a medium on which the desired mutants but not the parent will grow
Membrane Filtration
Technique used to count microorganisms in liquids that contain relatively few cells; the cells are caught on a paper-thin filter
Spread-Plate Method
Technique used to cultivate bacteria by uniformly spreading a suspension of cells onto the surface of an agar plate
Fluorescence in situ Hybridization (FISH)
Technique used to detect a given nucleotide sequence within intact cells on a microscope slide.
Colony Blotting
Technique used to determine which colonies on an agar plate contain a given nucleotide sequence.
Slime Mold
Terrestrial organism composed of amoeboid cells that live on soil, leaf litter, or the surfaces of decaying vegetation; similar to fungi but not related genetically
Which of the following inhibits protein synthesis by blocking attachment of tRNA to the ribosome?
Tetracyclines
Plus (+) Strand
The DNA strand complementary to the strand used as a template for RNA synthesis. An mRNA molecule that can be translated to make a protein; also called the positive strand or sense strand, DNA strand.
Minus (-) Strand
The DNA strand used as a template for RNA synthesis. The complement to the plus (or sense) strand of RNA. Also called the negative strand or antisense strand, DNA strand.
Resolving Power
The ability to distinguish two objects that are very close together
Clostridium paradoxum grows optimally at 55 C, pH 9.3 and it will not grow in the presence of oxygen. Characterize this bacterium based on its temperature, pH, and oxygen requirement.
The bacterium is a thermophile, alkaliphile and strict anaerobe.
Clostridium paradoxum grows optimally at 55oC, pH 9.3, and it will not grow in the presence of oxygen.
The bacterium is a thermophile, alkaliphile, and strict anaerobe.
Energy
The capacity to do work
Proofreading
The detection and removal by DNA polymerase of an incorrect nucleotide incorporated as DNA is synthesized
Gene
The functional unit of the genome; it encodes a product, most often a protein.
Periplasm
The gel-like material that fills the region between the cytoplasmic membrane and the outer membrane of Gram-negative bacteria.
Domain
The highest level in biological classification. There are three domains : Bacteria, Archaea, and Eukarya.
Base-Pairing
The hydrogen bonding of adenine (A) to thymine (T) and cytosine (C) to guanine (G)
Cell Envelope
The layers surrounding the contents of the cell; includes the cytoplasmic membrane, cell wall, and capsule (if present)
Objective Lens
The lens or series of lenses of a compound microscope that is closest to the specimen
ID50
The number of organisms that, when administered, will cause infection in approximately 50% of hosts
Phenotype
The observed characteristics of a cell.
Which of the following statements is not true about redox reactions?
The oxidizing agent is oxidized
A mutation was caused by a deletion of three base pairs. What is the impact of this mutation?
The polypeptide has one less amino acid.
A mutation was created by a deletion of three base pairs. What is the impact of this mutation?
The polypeptide has one less amino acid.
Germinate
The process by which an endospore or other resting cell becomes a vegetative cell
Phagocytosis
The process by which certain cells ingest particulate matter by surrounding and enveloping those materials, bringing them into the cell in a phagosome
Translation
The process by which the information carried by mRNA is used to synthesize the encoded protein.
Transcription
The process by which the information encoded in DNA is copied into RNA.
Biogenesis
The production of living things from other living things, as opposed to spontaneous generation
Nucleobase
The purine or pyrimidine ring structure found in nucleotides; also called a base
After the conjugation of an Hfr cell with an F- cell, _____.
The recipient remains F-
Phase Variation
The reversible and random alteration of expression of certain bacterial structures such as fimbriae by switching on and off the genes that encode those structures
PCR Product
The target fragment amplified exponentially in a PCR reaction
Chemiosmotic Theory
The theory that a proton gradient is formed by the electron transport chain and then used to power ATP synthesis
Biotechnology
The use of microbiological and biochemical techniques to solve practical problems and produce valuable products
Microorganisms such as bacteria are suitable research tools because ________.
Their metabolic and genetic properties are more or less the same with higher forms of life. Bacteria are much easier to study.
Endosymbiotic Theory
Theory that the ancestors of mitochondria and chloroplasts were bacteria that had been residing within other cells in a mutually beneficial partnership
What happens to the carbon molecules in the acetyl CoA that goes through the citric acid cycle?
They become carbon dioxide.
What is the function of restriction enzymes?
They cut DNA at specific sequences.
Which is the function of restriction enzymes?
They cut DNA at specific sequences.
What are mycoplasmas resistant to penicillin and other B lactam drugs?
They do not have cell walls.
Why are mycoplasmas resistant to penicillin and other β lactam drugs?
They do not have cell walls.
Sex Pilus
Thin protein appendage required for attachment of two bacterial cells prior to DNA transfer by conjugation. The F pilus is an example
Which statement best describes the enzyme represented in the graphs?
This enzyme works best at a temperature of 35oC and pH 8
What is the purpose of making successive streaks in streak-plate method?
To dilute the cells.
Anneal
To form a double-stranded duplex from two complementary strands of nucleic acid
What is the purpose of staining?
To increase contrast.
The horizontal gene transfer that occurs via bacteriophage is ______.
Transduction
Vertical Gene Transfer
Transfer of genes from parent to offspring.
Pseudopods
Transient arm-like extensions formed by phagocytes and protozoa; they surround and enclose extracellular material, including bacteria, during the process of phagocytosis
Facilitated Diffusion
Transport process that moves compounds across a membrane down a concentration gradient; does not require energy
Segments of DNA capable of moving from one area in the DNA to the another are called ______.
Transposons
Sanitization
Treatment to reduce the microbial population to a level that meets accepted health standards
Decontamination
Treatment to reduce the number of pathogens to a level considered safe
Which of the following microorganisms cause syphilis?
Treponema pallidum
The vegetative or feeding form of protozoa is called _____.
Trophozoite
"Genetically engineered" protein such as human insulin produced by the bacterium E. coli is safer and less expensive than insulin isolated from animals.
True
A disinfectant that destroys the envelope of a virus make the virus non-infectious (can longer infect its host cell).
True
Even though viroids and viruses are not made up of cells, they are included in the microbial world because they cause diseases in humans, animals, and plants.
True
In bacterial tansformation, only competent cells are transformed.
True
Refer to figure 3. Which of the tubes will give a higher absorbance? If 1.0mL of the broth in each tube is plated in two separate TSA agar plates. Which tube will give a higher cfu?
Tube B will give a higher absorbance and higher cfu.
Extensively Drug-Resistant Tuberculosis (XDR-TB)
Tuberculosis caused by strains of Mycobacterium tuberculosis resistant to isoniazid and rifampin, plus three or more second-line antimicrobials
Multidrug-resistant Tuberculosis (MDR-TB)
Tuberculosis caused by strains of Mycobacterium tuberculosis that are resistant to isoniazid and rifampin
Transfer RNA (tRNA)
Type of RNA molecule involved in interpreting the genetic code; each tRNA molecule carries a specific amino acid.
Messenger RNA (mRNA)
Type of RNA molecule translated during protein synthesis.
Intermediate-Level Disinfectants
Type of chemical used to destroy all vegetative bacteria including mycobacteria, fungi, and most, but not all, viruses
Competitive Inhibition
Type of enzyme inhibition that occurs when the inhibitor competes with the normal substrate for binding to the active site
Non-Competitive Inhibition
Type of enzyme inhibition that results from a molecule binding to the enzyme at a site other than the active site
Restriction Enzyme
Type of enzyme that recognizes a specific nucleotide sequence and then cuts the DNA within or near that site.
Beta-Hemolysis
Type of hemolysis characterized by a clear zone around a colony grown on blood agar
Alpha Hemolysis
Type of hemolysis characterized by a zone of greenish clearing around colonies grown on blood agar
Generalized Transduction
Type of horizontal gene transfer that can occur when a phage carries a random piece of bacterial DNA; the phage acquires that DNA when a packaging error occurs during the assembly of phage particles
Specialized Transduction
Type of horizontal gene transfer that can occur when a temperate phage carries specific bacterial genes; the phage acquires those genes when an error occurs as the prophage excises from a lysogenic cell's chromosome
Bright-Field Microscope
Type of light microscope that illuminates the field of view evenly
Phase-Contrast Microscope
Type of light microscope that uses special optical devices to amplify the difference in the refractive index of a cell and the surrounding medium, increasing the contrast of the image
Transmission Electron Microscope (TEM)
Type of microscope that directs a beam of electrons at a specimen; used to observe details of cell structure
Dark-Field Microscope
Type of microscope that directs light toward the specimen at an angle, so that only light scattered by the specimen enters the objective lens
Differential Interference Contrast (DIC) Microscope
Type of microscope that has a device for separating light into two beams that pass through the specimen and then recombine, resulting in the three-dimensional appearance of material in the specimen
Scanning Electron Microscope (SEM)
Type of microscope that scans a beam of electrons back and forth over the surface of a specimen
Scanning Laser Microscopes (SLMs)
Type of microscope that scans laser beans across a specimen, thereby allowing a three-dimensional image of a thick structure to be constructed
Cyclic Photophosphorylation
Type of photophosphorylation in which electrons are returned directly to the chlorophyll; phototrophs use this to synthesize ATP without generating reducing power
Non-Cyclic Photophosphorylation
Type of photophosphorylation in which high-energy electrons are drawn off to generate reducing power; electrons must still be returned to chlorophyll, but they come from a source such as water
Receptor-Mediated Endocytosis
Type of pinocytosis that allows cells to internalize extracellular ligands that bind to the cell's receptors
Carriers
Type of protein found in cell membranes that transports certain compounds across the membrane; may also be called a permease or transporter protein
Receptor
Type of protein that binds to specific molecules in the environment, providing a mechanism for the cell to sense and adjust to its surroundings
Confocal Microscope
Type of scanning laser microscope
Atomic Force Microscope (AFM)
Type of scanning probe microscope that has a tip mounted so it can bend in response to the slightest force between the tip and the sample
Differential Staining
Type of staining procedure used to distinguish one group of bacteria from another by taking advantage of the fact that certain bacteria have distinctly different components
Group Translocation
Type of transport process that chemically alters a molecule during its passage through the cytoplasmic membrane
Naked Virus
Type of virus that does not have a lipid envelope
Non-Enveloped Viruses
Type of virus that does not have a lipid envelope
Vegetative Cell
Typical, actively multiplying cell
WOF radiations can damage the DNA by formation of dimers?
UV Light
Which of the following radiations can damage the DNA by formation of dimers?
UV light
Human Microbiome Project (HMP)
Undertaking that uses genomics to study the normal microbiota of the human body
Yeasts
Unicellular fungi that are not chytrids.
Bacterium A is an aerotolerant anaerobe. If this bacterium is grown in thioglycolate tubes, to what area in the tubes the growth of the bacterium can be observed?
Uniformly throughout the tube
Pleomorphic
Varying in shape
Trophozoite
Vegetative feeding form of some protozoa
Endosome
Vesicle formed when a cell takes up material from the surrounding environment using the process of endocytosis
The __________ method provides an estimate of the CFUs (colony-forming units) in a sample.
Viable Plate Count
Productive Infection
Viral infection in which more viral particles are produced.
Latent Infection
Viral infection in which the viral genome is present but not active, so viral particles are not being produced.
Lytic Infection
Viral infection of a host cell with a subsequent production of more viral particles and lysis of the cell
Nucleocapsid
Viral nucleic acid and its protein coat
Below are infectious agents and their composition. Which is mismatched?
Viroids - DNA only
Differentiate viroids from viruses?
Viroids are composed of RNA only and viruses have DNA or RNA.
Which of the following you do at home to control microbes?
Washing and scrubbing materials with soaps and detergents.
Anaerobic
Without molecular oxygen (O2)
In the application, human genes are inserted into animals to produce cells, tissues, and organs that are then introduced into the human body , reducing the likelihood of rejection.
Xenotransplant
A light microscope has a resolution of 0.3 um. Will this microscope be able to resolve (determine two objects as separate) two objects 0.4 um apart? Will it be able to resolve two objects that are 0.004 um apart?
Yes ; no
Which of the following are the sexual spores of common bread mold?
Zygospores
Lactic Acid Bacteria
a Group of Gram-positive bacteria that generate lactic acid as the major end product of their fermentative metabolism
Which of the following microscopes will give a greater resolution?
a microscope with resolving power of 0.20 um
Give the importance of your normal microbiota. a. They prevent attachment of pathogens. b. They make the environment unfavorable for pathogens to grow. c. They utilize nutrients required by pathogens to grow. d. They produce antimicrobial substances.
a, b, c & d
Give the importance of your normal microbiota. a. They prevent attachment of pathogens b. They facilitate the growth of pathogens c. They utilize nutrients required by pathogens d. They produce antimicrobial substances
a, c, and d
What is the final electron acceptor in ethanol fermentation? It is a one-word answer and spelling matters.
acetaldehyde
Which process generates or produces the most ATP from catabolism of glucose?
aerobic cellular respiration
Which of the following groups of microorganisms can grow in the presence of oxygen but do not use oxygen to harvest energy or make ATP?
aerotolerant anaerobes
What composed the glycan chain only of peptidoglycan?
alternating NAM-NAG only
During translation, each codon specifies a/an _________ to be placed at the corresponding position along a polypeptide.
amino acid
What prokaryotes thrive in extreme conditions such as high heat, acidity, alkalinity and salinity? It is a one-word answer and spelling matters.
archaea
The correct order for the stages of T4 phage replication is ________.
attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release
Salmonella his- is a/an (auxotroph or prototroph) and (has or lacks) a functional gene for histidine synthesis.
auxotroph ; lacks
Pasteur repeated Spallanzani's experiment with modification/s. What is/are the modifications? a. He boiled the broth. b. He bent the neck of the flask. c. He allowed air to enter the flask. d. He completely sealed the opening of the flask.
b and c only
Put the following events in the construction of a recombinant DNA molecule in the correct order: a. Plasmid is introduced into bacteria b. Gene of interest and plasmid DNA are cut by restriction enzyme c. Gene of interest is joined to plasmid DNA d. Bacteria are grown of on suitable culture medium.
b-c-a-d
A microbial control agent that kills bacteria is ________.
bactericidal
The causual agent of whooping cough is a _____.
bacterium
You isolated a microorganism from the soil and your analysis shows that the microorganism is unicellular and has a cell wall made of peptidoglycan, what could be this microorganism? It is a one-word answer (in singular) and spelling matters.
bacterium
A cell that has a net negative charge on its surface will readily take basic stain or acidic stain?
basic stain
The conversion of ammonium to nitrate could be accomplished by the presence of ________.
both Nitrosomonas and Nitrobacter
Which of the following uses inorganic phosphate to phosphorylate ADP to ATP?
both oxidative level phosphorylation and photophosphorylation
Antibacterial medications that affect cell membrane have low therapeutic index because ________.
both prokaryotes and eukaryotes have similarities in structure and composition of cell membrane
The liquid inside a red blood cell has 0.9% salt. If this cell is placed in a beaker with pure distilled water, the cell will ______.
burst because the collusion in the beaker is hypotonic to solution inside the cell
The liquid inside a red blood cell has 0.9% salt. If this cell is placed in a beaker with pure distilled water, the cell will ________.
burst because the solution in beaker is hypotonic to solution inside cell
How does enzyme speed up the rate of a chemical reaction?
by decreasing the activation energy
How is an autoclave able to achieve temperatures higher than that of boiling water?
by increasing the pressure
Put the following events in the correct order to show the basic steps of rDNA technology. a. Recombinant plasmid is inserted into bacteria. b. Bacteria with recombinant plasmid are grown on suitable culture medium. c. Gene of interest and plasmid are isolated and cut by the same restriction enzyme. d. Gene of interest is joined to plasmid.
c-d-a-b
The genetic material of viruses is enclosed by a protein coat called ________. It is a one-word answer and spelling matters.
capsid
The shape of the virus is determined by its ______.
capsid
What is the action of X-rays on DNA?
cause single and double strand breaks
All are effects of the presence or organic matter on the action of antimicrobial agents except ________.
causes the cells to form endospores
It is the diffusion of protons through the ATP synthase in the electron transport system. It is a one-word answer and spelling matters
chemiosmosis
The microorganisms that use carbohydrates as sources of carbon and energy are called ________. It is a one-word answer and spelling matters.
chemoheterotrophs (or chemoorganoheterotrophs)
Which of following are the dormant resting stages of Streptomyces sp.?
conidia
The horizontal gene transfer that requires cell-to-cell contact is ________. It is a one-word answer (singular) and spelling matters.
conjugation
The first step in bacterial conjugation is ________.
contact between the two cells
In the presence of glucose, the lac operon is not transcribed because glucose inhibits the synthesis of _______.
cyclic AMP
What facilitates the binding of catabolite activator protein (CAP) in the CAP site in the operon?
cyclic AMP
Which of following resting stages in prokaryotes are used for nitrogen fixation?
cysts
What is the correct order of binary fission from first to last? a. DNA is moved into each future daughter cells. b. Cross wall formation. c. Cell divides into two cells. d. DNA replicates e. Cells separate
d-a-b-c-e
Arrange the following steps in order from first to last to prepare a heat fixed bacterial smear. a. Air dry the thin film. b. Spread a thin film of bacteria over glass slide. c. Pass the slide with the film over flame of Bunsen burner. d. Get a clean glass slide.
d-b-a-c
Arrange the following steps in order from first to last to prepare a heated fixed smear. a. Air dry the thin film b. Spread a thin film of bacteria over glass slide c. Pass the slide with the film over the flame of bunsen burner d. Get a clean glass slide
d-b-a-c
Boiling kills microorganisms by ________.
denaturation of proteins
Parasitic worms, even meters-long tapeworms, are studied in microbiology because ________.
diagnosis usually involves microscopic examination of patient samples
Blood agar can support growth of almost all bacteria and it can determine three types of hemolysis. What type of culture medium based on function is blood agar?
differential culture medium only
Selective toxicity means the ________.
drug is more harmful to the pathogens than to human cells
Joan wants to discover a microbe capable of degrading an environmental contaminant. Which of the following is the process she should use?
enrichment culture
Drug-resistant populations of microbes arise when ________.
exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells
What groups of microorganisms grow throughout thioglycollate agar tubes but there is more growth on the surface or near the surface. It is a two-word answer and spelling matters.
facultative anaerobes
What microorganisms based on oxygen requirement grow throughout thioglycollate agar but there is no more growth on the surface or near the surface.
facultative anaerobes
This facultative anaerobic bacterium can ONLY use cellular organic compounds as final electron acceptors. To generate ATP, this bacterium would use __________.
fermentation
Which of the following inhibits the action of topoisomerases?
fluoroquinolones
If an antimicrobial agent kills disease-causing yeast, the agent is _____.
fungicidal
Replacing a patient's defective gene with a fragment containing a functional gene is
gene therapy
__________ can be used to advise prospective parents about their risk of transmitting genetic disorders, such as Huntington's Disease, to their offspring.
genetic screening
In photosynthesis, CO2 is reduced to __________
glucose
Extreme ________ are microorganisms that thrive in salt lakes, soda lakes and brines. It is a one-word answer (plural) and spelling matters.
halophiles
They are specialized hyphae used by parasitic fungi to derive nutrients from other living organisms. It is a one-word answer and spelling matters.
haustoria
What is the relationship of optical density (OD) to the concentration of cells in a broth culture?
high OD > high concentration of cells
As the electrons are passed from one acceptor to another in the ETS in bacteria, the H+ concentration outside the plasma membrane (increases/decreases)
increases
A viroid is a(n) ________.
infectious piece of RNA without a capsid
Protoplast fusion is a technique used for __________.
inserting DNA into cells
The disinfectant that can kill mycobacteria but not endospores are the ________.
intermediate level disinfectant
The disinfectant that can kill mycobacteria but not endospores are the __________
intermediate level disinfectant
The relationship of wavelength to resolving power is directly proportional or inversely proportional.
inversely proportional
Bdellovibrio ________.
is a parasite of bacteria
In the lac operon, the presence of __________ cause the release of the repressor protein from the DNA, facilitating transcription.
lactose
In this animal virus infection, the viral genome (provirus) remains silent in host cell but, can reactivate.
latent infections
A drug with high therapeutic index is ________.
less toxic to the patient
A set of clones representing the entire genome of an organism is known as a gene ________.
library
What is the enzyme that is used to join the DNA together? It is a one-word answer (singular) and spelling matters.
ligase
At what phase of the growth curve generation time is measured? At what stage microbes are sensitive to antimicrobial agents like penicillin?
log phase ; log phase
Liquid media containing heat-sensitive components would best be sterilized by __________.
membrane filtration
Given the hypothetical DNA template below, what is the amino acid sequence of the polypeptide that will be synthesized? Polypeptide begins with start codon and ends with stop codon. "GGG-TTT-TAC-AGA-CAC-CCC-ACT-AAA"
met-ser-val-gly
Single-strand DNA molecules are fixed to a glass slide or nylon membrane for the production of ________.
microarrays
The insertion of foreign DNA directly into a cell's nucleus using a glass micropipette is called ________.
microinjection
Refer to figure 8. Figure A shows a normal bacteria expressing the gene. The sequence of polypeptide is Met-Lys-Phe-Gly. In Figure B, a point mutation occurred, a T was incorporated instead of C. What type of point mutation is it?
missense mutation
The terms yeast, mold, and mushrooms refers to fungal ________.
morphology
The fruiting structure of basidiomycetes is called ________. It is a one-word answer (singular) and spelling matters.
mushroom
________ are chemical and physical agents used to create changes in the genome of the microorganisms to effect desired changes in the phenotype of the microorganisms. It is a one-word answer (plural) and spelling matters
mutagens
What is the symbiotic relationship between cyanobacterium and fungi?
mutualism
A tangle of fungal hyphae is generally known as a ______.
mycelium
What is the waxy substance present only in acid-fast positive bacteria and absent in acid-fast negative bacteria?
mycolic acid
The association of plants and fungi is called ________. It is a one-word answer and spelling matters.
mycorrhiza
In gel electrophoresis, DNA molecules which have a net (negative or positive) charge move towards the (negative or positive) side of the gel.
negative; positive
Stethoscope is what type of medical instrument based on risk for transmitting infectious agents?
non-critical instrument
A mutation that changes a codon that specifies an amino acid to a stop codon, resulting in premature termination of polypeptide synthesis is called ________ mutation. It is a one-word answer and spelling matters.
nonsense
What is the symbiotic relationship between Bdellovibrio sp. and E. coli?
parasitism
Which of the following processes is used to "amplify" DNA, making large numbers of copies from a small sample?
polymerase chain reaction
Which of the following microorganisms do not have cell wall?
protozoa
The process of microbial spoilage below is ________. Proteins + proteolytic microbes à amino acids + amines + NH3 + H2S
putrefaction
Which of the following methods to quantitate animal viruses can determine ID50 or LD50?
quantal assay
Washing your hands with plain soap can control the spread of COVID-19 because the process ________.
removes microorganisms mechanically
Washing your hands with plain soap can control the spread of COVID-19 because the process _________.
removes microorganisms mechanically
What enzyme is used to copy nucleotide sequences to make cDNA? It is a two-word answer (singular) and spelling matters.
reverse transcriptase
They are specialized hyphae used by saprophytic fungi for absorption of nutrients It is a one-word answer (plural) and spelling matters.
rhizoids
Tumbles occur when the flagella________.
rotate clockwise
Spirochetes
s Long helical bacteria that have a flexible cell wall and endoflagella
An antibiotic made by microorganisms and modified by chemists in the laboratory is called ________.
semi-synthetic
Sphaerotilus and Leptothrix are examples of ________.
sheathed bacteria
Drugs with (longer / shorter) half-life are given to patients more frequently?
shorter
What subunit of bacterial RNA polymerase recognizes the promoter sequence? It is a two-word answer (singular) and spelling matters.
sigma factor
Classification of viruses is based on all of the following except ________.
size of virus
What type of culture medium is nutrient agar based on form and composition? Components of the medium are given below. -Nutrient agar g/L -Peptone - 3 -Beef extract - 5 -Agar - 15
solid and complex
In chytridiomycetes, ___________.
sporophyte is the diploid multicellular stage and gametophyte is the haploid multicellular stage
Which is the function of reverse transcriptase?
synthesizes DNA from an RNA template.
What occurs in the initiation stage or translation?
tRNA-fmet) attaches to start codon and then larger body of ribosome combines with smaller body
F+ refers to a cell containing ________.
the F plasmid
Which of the following pathways is specifically inhibited by trimethoprim?
the conversion of dihydrofolic acid to tetrahydrofolic acid
Microwaves do not kill organisms directly but kill by ________.
the heat they generate in a product
After the conjugation of an Hfr cell with an F- cell, ________.
the recipient remains F-
The toxicity of a given drug is expressed as the ________.
therapeutic index
The horizontal gene transfer that occurs via bacteriophages is ________.
transduction
When the recombinant plasmid is introduced to E. coli, what type of gene transfer is it?
transformation
Vancomycin-intermediate S. aureus (VISA)
vancomycin-intermediate Staphylococcus aureus (VISA)
Vancomycin-Resistant S. aureus (VRSA)
vancomycin-resistant Staphylococcus aureus (VRSA)
Vancomycin-Resistant Enterococci (VRE)
vancomycin-resistant enterococci (VRE)
You are using a Petroff-Hausser counting chamber to determine the number of cells in a liquid culture. After diluting the original sample 10-fold, you place the dilution into the chamber. You count an average of 15 cells in five different squares. How many cells per ml were present in your original sample?
x= 15 x (1.25x10^6) x 10 = 1.9 x 10^8 cells/ml
They are unicellular microorganisms with nucleus and cell wall made up of chitin. It is a one-word answer (in plural) and spelling matters.
yeasts
