MCB3020 Bacusmo Final Exam (Cumulative)
After the initiation step of protein synthesis transfer RNAs carrying amino acids bind to the ribosome at the _________.
"A" site
Transposons can cause mutations by_______.
"Jumping" into a gene and disrupting its function
The initiating transfer RNA carrying formylmethionine, binds to which site?
"P" site
Transposons can cause mutations by _________.
"jumping" into a gene and disrupting its function
What is the CDC? Where are they located and what do they do?
-Centers for Disease Control and Prevention -Atlanta, GA -Functions as national focus for developing and applying disease prevention and control, environmental health, and health promotion and health education activities designed to improve the health of the people
Outline the steps involved in Koch's postulates
1. the microorganism must be present in every case of the disease but absent from healthy organisms 2. the suspected microorganisms must be isolated and grown in a pure culture 3. the same disease must result when the isolated microorganism is inoculated into a healthy host 4. the same microorganisms must be isolated again from the diseased host
What feature is characteristic of double-stranded DNA?
10 base pairs per turn
Arrange the following events in the proper sequence for gene cloning.1 = Incorporate gene into bacterial plasmid.2 = Isolate DNA from organism containing desired gene.3 = Incorporate cloned gene into bacterial cells.4 = Fragment DNA with restriction enzyme.
2, 4, 1, 3
Examine the graph. Lines A, B, and C represent different microbes' survival in the presence of "XYZ" antimicrobial compound. How long should you treat surgical plastics to ensure the diverse population of microbes are sterilized?
4 hours
A 30x objective and a 20x ocular produce a total magnification of_______.
600x
If you start with one double-stranded DNA molecule and you perform SIX cycles of PCR, how many double-stranded copies of the DNA will you have?
64 (2^ power of number of cycles run)
Bacterial and archaeal ribosomes are known as _________ ribosomes, based on their sedimentation coefficient.,
70S
Bacterial and archaeal ribosomes are known as _________blank ribosomes, based on their sedimentation coefficient.
70S
New amino acids (other than the initial f-Met) enter at which site?
A
In which of the following situations did disease develop due to vertical transmission of the pathogen?
A fetus develops listeriosis after unpasteurized cheese infected with Listeria bacteria is consumed by the mother during pregnancy
Choose the best description of how filtration works to control microbes.
A filter is a solid material containing small holes that only allows liquids to pass but restricts larger substances from passing to a sterile environment.
Which will require a longer time to kill?
A larger population of microorganisms
Frameshift mutation
A mutation resulting from an insertion or deletion of bases that causes a change in the reading frame of the mRNA
Nonsense mutation
A mutation that changes a codon encoding an amino acid to a stop codon, resulting in premature termination of polypeptide synthesis
Silent mutation
A mutation that changes a codon into a different codon, but both codons specify the same amino acid; this causes no change in the resulting polypeptide
Missense mutation
A mutation that results in changing a codon such that a different amino acid is inserted
What are the components of an amino acid?
Amino group (positively charged at neutral PH), side chain- "the rest" of the molecule, carboxyl group- negatively charged at neutral pH
What is a viroid?
An infectious agent consisting of only RNA
What is a prion?
An infectious agent consisting of only protein
What is a virus?
An infectious agent made up of protein, nucleic acids and sometimes a lipid membrane
What is a eukaryote?
An organism characterized by having cells containing DNA in a membrane-bound organelle
All of the following are compoents of the mammalian host immune system EXECPT______.
Antingens
Old cultures of bacteria that have lost their ability to cause disease are said to be _________.
Attenuated
When type B blood is given to a person with type A blood______.
B antigen from the donor reacts with anti-B antibody in the recipient
Which of the following inhibits bacterial growth but doesn't kill bacteria?
Bacteriostatic agent
Horizontal gene transfer is the transfer of DNA_______
Between different genomes
Which of the following distinguishes the field of microbiology from other fields of biology?
Both the size of the organism studied and the techniques employed in the study of organisms.
What is industrial microbiology?
Branch of applied microbiology in which microorganisms are used in industrial processes such as the production of drugs, chemicals, and fuels
Which of the following is not part of the lichen association?
Brown algae
Which microbial control method best describes how an autoclave sterilizes material?
By heat
_________are hollow tube-like structures that hold some archaeal daughter cells together after cell division while _________are grappling hook-like structures that appear to attach archaeal cells to surfaces.
Cannulae; hami
_________blank are hollow tube-like structures that hold some archaeal daughter cells together after cell division while _________blank are grappling hook-like structures that appear to attach archaeal cells to surfaces.
Cannulae; hami
A nucleotide deletion in DNA replication_________.
Causes the amino acids inserted after the deletion to be incorrect
What governmental agency focuses on national and environmental health, as well as designs a set of health education activities to improve general health of the population?
Center for Disease Control and Prevention (CDC)
The organelle responsible for harvesting light as an energy source for photosynthesis is the _________.
Chloroplast
Examine the graph. Each line represents a different antimicrobial agent applied to the same microbe. Which antimicrobial agent is the most effective?
Compound C
Horizontal gene transfer can occur via_______.
Conjugation (transfer of DNA i.e., a plasmid) from one bacterial cell to another
Which of the following contribute(s) to the differences between the members of the Domain Archaea and the Domain Bacteria? A. Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids B. Archaea lack muramic acid. C. Archaea differ from bacteria in their tRNA composition, ribosome structure, and antibiotic sensitivity. D. All of the choices are correct.
D. All of the choices are correct.
Each of the following provides evidence in support of the primary role of RNA in the evolution of life EXCEPT _________. A. ATP (energy currency of the cell) is a ribonucleotide B. RNA can regulate gene expression C. some RNA molecules are catalytic D. RNA is less chemically stable than DNA E. RNA catalyzes peptide bond formation during protein synthesis
D. RNA is less chemically stable than DNA
Select all the differences between cellular DNA and cellular RNA to test your understanding these nucleic acids.
DNA is double-stranded, RNA is single-strandedDNA is double-stranded, RNA is single-stranded DNA nucleotides contain deoxyribose whereas RNA nucleotides contain ribose
PCR requires all of the following EXCEPT______.
DNA ligase- used in plasmid cloning and other related techniques
What is the most compelling reason why DNA rather than RNA, evolved to be the storage repository for genetic information in cellular life forms?
DNA molecules are more chemically stable than RNA molecules
If DNA were a positively charged rather than negatively charged, what change to the gel electrophoresis procedure must be made?
DNA must be loaded at the positive pole rather than at the negative pole.
What best describes transcription?
DNA-->RNA (RNA polymerase reading a DNA template to make RNA)
A researcher proposes that the relationship between a particular bacterial species that produces a fat-soluble vitamin is mutualistic with its insect host. Which of the following procedures would best test the researcher's hypothesis?
Determine which antibiotic kills the bacteria without harming the host, then administer this antibiotic to the insect and compare its growth with and without the vitamin.
The Gram-staining procedure is an example of______.
Differential staining
Vertical gene transfer is the transfer of DNA________.
During normal cell division
What are some of the reasons for the emergence of new diseases in recent decades?
Ecological distribution, increased drug use, sexual promiscuity, and an increase in the mobility of the population
Movement of charged molecules in an electrical field, which is used to separate nucleic acid fragments for recombinant DNA work, is called _________.
Electrophoresis
Which cell type ranges in size from about 10-100 µm, has 80s ribosomes, and has internal compartments bounded by membranes?
Eukarya
Differentiate between the types of microorganisms studied by microbiologists.
Eukaryote- cells containing DNA in membrane bound organelleProkaryote- cell lacking membrane-bound nucelusPrion- infectious agent consisting only of proteinViroid- infectious agent consisting only of RNAVirus- infectious agent made of protein, nucleic acids, and sometimes a lipid membrane
Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called _________.
Eukaryotes
A student is observing microorganisms in a sample of pond water. One organism of interest has an obvious nucleus, small oval structures containing a green pigment, and does not appear to be motile. In which of the following groups would this microbe most likely be classified?
Eukaryotes (Algae)
What is herd immunity?
Explains the resistance of a population to infection and to the spread of an infectious organism due to high level of immunity of a large percentage of the population.
Colonization specifically refers to the multiplication of a pathogen on or within a host, and includes the resulting tissue invasion and damage.
False
During the lag phase of microbial growth, the cells are metabolically inactive.
False
If you remove the peptidoglycan layer from a Gram-positive cell, it would still stain purple with a Gram stain.
False
Koch's postulates were instrumental in establishing that the intracellular parasite Mycobacterium leprae is the causative organism of leprosy.
False
Like prokaryotic cells, most eukaryotic cells have an external cell wall.
False
T or F: The Gram stain can only be performed on cultures grown in liquid media.
False
T/F: A cell that is Hfr and a cell that is F+ can be the same cell.
False
T/F: A person with type O blood may receive blood from a person with type B blood.
False
T/F: A stop codon codes for an amino acid as well as the signal to stop.
False
T/F: Although developed over 100 years ago, Koch's postulates continue to be used to find the causative organism for all known human infectious diseases.,
False
T/F: Although similar in function the eukaryotic ribosome is generally smaller and more complex than bacterial and archaeal ribosomes.
False
T/F: Bacterial isolates from post-surgical infections of several patients on the same hospital floor demonstrate an increase in resistance to similar antibiotics. The pattern of antibiotic resistance in these cases is most likely due to vertical gene transfer among bacteria that carry resistance genes to bacteria that lack those genes.
False
T/F: During phagocytosis, the phagolysosome forms before the phagosome forms.
False
T/F: Edward Jenner's work in preventing rabies led to the use of the term vaccination to describe a type of procedure used in the prevention of disease.
False
T/F: Generally, exotoxins tend to be more heat stable than endotoxins.
False
T/F: Gram-positive bacteria have a structurally and chemically more complex cell wall than Gram-negative bacteria.
False
T/F: Gram-positive bacteria have a thinner layer of peptidoglycan than gram negative bacteria.
False
T/F: In a frameshift mutation all of the amino acids before the shift are changed.
False
T/F: In the host-parasite relationship, it is advantageous for the parasite to disable and kill its host as quickly as possible.
False
T/F: Inanimate materials involved in pathogen trasmission are called reservoirs.
False
T/F: Negative staining facilitates the visualization of bacterial capsules that are intensely stained by the procedure.
False
T/F: Scientists first focused on gene regulation at the level of translation, rather than transcription, because more was known about protein than nucleic acids at the time.
False
T/F: The Gram stain can only be performed on cultures grown in liquid media.
False
T/F: The earliest microbial fossils that have been found are dated from approimately 4.5 million years ago.
False
T/F: The innate response resists a particular foreign agent; moreover, innate immune responses improve on repeated exposure to the agent.
False
T/F: The skin surface is a very favorable environment for colonization by most microorganisms.
False
T/F: Viruses are not generally studied by microbiologists because they are not classified as living organisms.
False
The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.
False
The genetic code is expressed differently in bacterial and archaeal cells than in eukaryotic cells.
False
The mucociliary blanket is found in the digestive system of mammals.
False
The mucocillary blanket is found in the digestive system of mammals.
False
True or False: Although similar in function, the eukaryotic ribosome is generally smaller and more complex than bacterial and archaeal ribosomes.
False
True or False: Bacterial isolates from post-surgical infections of several patients on the same hospital floor demonstrate an increase in resistance to similar antibiotics. The pattern of antibiotic resistance in these cases is most likely due to vertical gene transfer among bacteria that carry resistance genes to bacteria that lack those genes.
False
True or False: Edward Jenner's work in preventing rabies led to the use of the term vaccination to describe a type of procedure used in the prevention of disease.
False
True or False: Generally, exotoxins tend to be more heat stable than endotoxins.
False
True or False: Inanimate materials involved in pathogen transmission are called reservoirs.
False
True or False: The bacterial initiator tRNA is fMet-tRNAiMet whereas the eukaryotic initiator tRNA lacks the formyl group on the amino moeity; Met-tRNAiMet. Archaea, which, like bacteria, lack a nucleus, utilize the same initiator tRNA as bacteria, fMet-tRNAiMet in the initiation of translation.
False
True or False: The earliest microbial fossils that have been found are dated from approximately 4.5 million years ago
False
True or False: The innate response resists a particular foreign agent; moreover, innate immune responses improve on repeated exposure to the agent.
False
T/F: During the PCR, the hydrogen bonds of the double-stranded DNA molecules are broken by the enzyme helicase.
False, HB broken by heating DNA
T or F: Immunization of a population has no effect on herd immunity.
False, immunization increases the levels of herd immunity
T/F: The bacterial initiator tRNA is fMet-tRNAiMet whereas the eukaryotic initiator tRNA lacks the formyl group on the amino moeity; Met-tRNAiMet. Archaea, which, like bacteria, lack a nucleus, utilize the same initiator tRNA as bacteria, fMet-tRNAiMet in the initiation of translation.,
False- archaea use Met-tRNAiMet in translation initiation (same as eukaryotes)
T/F: Restriction enzymes cut DNA at random sites
False- restriction enzymes cut at very specific sites on DNA called palindromes
Which of these techniques sterilizes on the basis of the size of the microbes to be removed?
Filtration
Tears protect the eyes by ________.
Flushing and Lysozyme
An inanimate object that may be contaminated with a pathogen is called a ________.
Fomite
What DNA sequence pairing is the most stable?
GCGTGCACCGCACGTGGuanine is linked to cytosine with three hydrogen bonds as opposed to two with adenine to thymine. The three hydrogen bonds lend more stability, thus allowing strands with the most guanine and cytosine to be more stable.
Lysosomes are membrane-bound vesicles that arise from the______.
Golgi apparatus
Endotoxin is released when _________.
Gram-negative pathogens lyse or divide
Compare and contrast horizontal and vertical gene transfer.
HORIZONTAL: -genes from one independent, mature organism transferred to another mature organism-conjugation-transduction-transformationVERTICAL: -fusion of gametes-from parent to offspring-crossing-over between sister chromosomes during meiosis
External structures that are found in archaea but not bacteria are _________blank
Hami
External structures that are found in archaea but not bacteria are_____.
Hami
Which microbial control method best describes the process of pasteurization?
Heat
The enzyme_____unzips and unwinds the DNA molecule.
Helicase
Blood cell development occurs in the bone marrow of mammals during the process of ________.
Hematopoesis
When an F plasmid integrates into the host chromosome, the strain is referred to as_________.
Hfr
What is sour mash inoculated from?
Homolactic bacterium
The lysosome contains________enzymes.
Hydrolytic
The inhalation of cigarette smoke and similar pollutants has a gradual effect on cilia lining the respiratory tract, first causing the beating to slow and eventually stop. How does this change in cilia most directly impact the resistance mechanisms of the host?
Innate host immunity due to mechanical barrier protection would be lost
Who was the first epidemiologist and what did he study?
John Snow - studied series of Cholera outbreaks; discovered the disease came from infected drinking water
Who was the first Epidemiologist? What did they study?
John Snow, studied cholera outbreak in London, figured out that the main source of the disease was waste contaminated water, which propagated the spread of the disease
What is an example of yeast-lactic fermentation?
Kefir
In the following list of scientists, who developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?
Koch
What is an example of probiotics?
Lactobacilli and Bifidobacteria in yogurt
What are the four microbial genera used in production of fermented dairy products?
Lactobacillus, Lactococcus, Leuconostoc, and Streptococcus
Mutations that result in the death of an organism when expressed are called __________ mutations.
Lethal
Antiseptic surgery was pioneered by _________.
Lister
Antiseptic surgery was pioneered by________.
Lister
Which of the following is NOT a virulence factor encoded by a pathogenicity island?
Lysozyme
After the ribosome moves to the next codon on the mRNA, the growing peptie chain is found in which position(s)?
P
In the following list of scientists who provided the evidence needed to discredit the concept of spontaneous generation?
Pasteur
Choose the term that identifies the type of bond that joins amino acids in proteins.
Peptide bond
What type of bond is found connecting amino acids together during protein synthesis?
Peptide bonds
The correct structure of DNA components can be presented as_______.
Phosphate-sugar-base
A classification system based on evolutionary relationships is called a ______ system.
Phylogenetic
Which of the following features of a pathogen is not considered to be a virulence factor when establishing infection within a host?
Pigment production
Which of the following structures are external to both bacterial and archaeal cells?
Pili
The abnormal form of the protein is designated_______.
PrPSc
Which of the following processes is not one that is common to all symbionts?
Predation
After the decolorizer has been added, Gram-positive organisms are stained _________ and Gram-negative organisms are stained _________.
Purple, colorless
After the mordant has been added, Gram-positive organisms are stained_______ and Gram-negative organisms are stained _________.
Purple, purple
Each of the following provides evidence in support of the primary role of RNA in the evolution of life EXCEPT _________.
RNA is less chemically stable than DNA
What best describes translation?
RNA-->Protein (ribosomes reading messenger RNA to produce protein)
Plasmids that have genes that decrease bacterial susceptibility to antibiotics are called __________ factors.
Resistance
What is fermented in bread making?
Saccharomyces cerevisiae (baker's yeast)
In the Gram-staining procedure, the counterstain is _________.
Safranin
During the investigation of a convenience store robbery, witnesses report that the perpetrator exited through a main entry door without wearing gloves. The police are holding a prime suspect in custody while samples from the door are collected and analyzed for a DNA match. Since the door was handled by many people before the robbery, how will the forensics department distinguish the suspect's DNA from the DNA of others using PCR?,
Sequence-specific primers to the suspect's DNA will be used for PCR amplification.
When an F' plasmid acts as the donor in a mating, which of the following do(es) not happen?,
Some chromosomal genes NOT on the plasmid are transferred.
When an F' plasmid acts as the donor in a mating, which of the following do(es) not happen?
Some chromosomal genes not on the plasmid are transferred.
Rigid bacteria with a helical cell shape are called______.
Spirillia
Flexible bacteria with a helical shape are called______.
Spirochetes
_________ mutations arise occasionally in all cells and in the absence of any added agent.
Spontaneous
In which of the following areas of the human body do secretions play the greatest role in preventing microbial colonization?
Stomach
What is environmental microbiology?
Study of the cumulative impact of microbial processes occurring in the environment, both in specific biomes and on global scale
Select the correct statement about archael ribosomes.
The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.
Which is a false statement regarding riboswitches?
The effector molecules that bind to riboswitches are proteins.
what is an index case?
The first infection of an outbreak
What statement about DNA replication is true?
The leading strand is replicated continuously, while the lagging strand is replicated discontinuously.
The nucelic acid seuqnece in mRNA is determined by_______.
The nucleotide sequence in DNA.
Which of the following is useful in distinguishing between bacterial, archaeal, and eukaryotic cells?
The presence of membrane-delimited organelles within the cytoplasm
What does public health surveillance involve?
The proactive evaluation of emerging infectious agents, human behaviors, lifestyle choices, and genetic backgrounds
What is systematic epidemiology?
The study of the ecological and social factors that influence the development of emerging and reemerging infectious disease
Which is a primary reason that females are at greater risk of a urinary tract infection than are males?
The urethra is shorter in women; therefore, bacteria are closer in proximity to the bladder.
Organisms that grow near deep-sea volcanic vents are likely to be_______.
Thermophilic
Which of the following is/are true of capsules?
They help bacteria escape phagocytosis by host cells. They prevent entry of many bacterial viruses. They retain water and help prevent desiccation of the bacteria. [All of the choices are correct]
Predict the outcome of protein synthesis if a gene undergoes a mutation in its anticodon region where a charged tRNA recognizes a nonsense mutation.
Transcription and translation both would continue.
All eukaryotes have a membrane-delimited nucleus.
True
Archaeal and bacterial pili are identical in structure and function.
True
Cervical mucus has antibacterial activity.
True
Coral bleaching where the photosynthetic endosymbiont is lost or becomes nonfunctional can be caused by temperature increases as small as 2oC.
True
DNA replication results in two identical daughter molecules each consisting of one old (original) strand and one newly synthesized strand.
True
Genetic engineering methods have been used to produce vaccines.
True
Gram staining divides bacterial species into two groups based on differences in cell wall structure.
True
In order to stain flagella so that they may be readily observed by light microscopy, it is usually necessary to increase their thickness.
True
Insects frequently contain bacteria in their cytoplasm, and these bacteria form a mutualistic association with their host.
True
Invisible living creatures were thought to exist and cause disease long before they were ever observed.
True
Lactobacillus contributes to the antimicrobial defenses for the adult female reproductive tract by making lactic acid to lower the pH.
True
Macrophages are phagocytic cells.
True
Mordants increase the binding between a stain and specimen.
True
Some microorganisms are useful in bioremediation processes that reduce the effects of pollution.
True
T or F: Acetone can be used as the decolorizer in the Gram stain procedure.
True
T or F: Control measures for microorganisms should be directed toward the part of the disease cycle that is most susceptible to control.
True
T or F: Epidemiologists frequently draw on knowledge from the field of statistics.
True
T or F: Light rays are refracted (bent) when they cross the interface between materials with different refractive indices.
True
T or F: Pasteurization is used to kill pathogens and retard spoilage.
True
T or F: Vaccines stimulate immunity by presenting the body with novel antigens, which causes the body to develop antibodies to fight the antigens.
True
T/F: A structural gene encodes information (sequence of amino acids) for a specific protein.
True
T/F: Acetone can be used as the decolorizer in the Gram Stain procedure.
True
T/F: Asymmetrical spacing of the backbones of the DNA double helix generates major and minor grooves.
True
T/F: Before bacteria can establish an infection, they must be able to overcome resident microorganisms in direct competition for space and nutrients.,
True
T/F: Disease symptoms are believed to be the result of dense aggregates of abnormal protein.
True
T/F: Doubled-stranded DNA consists of two antiparallel strands meaning that one strand is oriented in the 5' to 3' direction, while the other is oriented in the 3' to 5' direction.,
True
T/F: During replication the point where separation of the DNA double helix occurs is called the replication fork.,
True
T/F: Genes for antibiotic resistance can be found in antibiotic-producing bacteria as well as in non-antibiotic-producing bacteria.
True
T/F: Horizontal gene transfer occurs frequently between the nuclear, mitochondrial, and chloroplast genomes of some eukaryotes.
True
T/F: In some inherited cases, the normal prion protein can convert spontaneously to the abnormal form, but at a slow rate.
True
T/F: In the Sanger method examining the electrophoresis gel and reading from bottom to top, one base at a time, gives the sequence of DNA.,
True
T/F: Inflammation is a nonspecifc defensive reaction to a tissue injury
True
T/F: Lactobacillus contributes to the antimicrobial defenses for the adult female reproductive tract by making lactic acid to lower the pH.
True
T/F: Lysosomes function in the destruction and recycling of old organelles.
True
T/F: Microorganisms show differential sensitivity to antimicrobial agents.
True
T/F: PCR can be used to amplify DNA from any source
True
T/F: People with type O blood can be universal donors because their red blood cells do not contain either A antigen or B antigen on their surface.
True
T/F: The addition of a single nucleotide to the DNA sequence causes a frameshift mutation.
True
T/F: The amino acid sequence of a protein determines its shape and specifc function.
True
T/F: The endosymbiotic hypohtesis is generally accepted as the origin of eukaryotic organelles.
True
T/F: The enzymes found in lysosomes were synthesized by ribosomes located on the endoplasmic reticulum.
True
T/F: The only organisms to produce endotoxins are Gram-negative bacteria.
True
T/F: The relationship between specific bacteria and specific diseases was first demonstrated by Koch.
True
T/F: The shorter urethra in females is one reason why urinary tract infections are more common in females than in males.
True
T/F: To sequence DNA by the Sanger method, the DNA must first be made in single-stranded form. DNA sequencing is a technique for determining the complete sequence of bases (i.e., As, Ts, Gs, and Cs) for a particular piece of DNA. Sanger sequencing is the most popular method for DNA sequencing. ,
True
T/F: When counting isolated colonies on an agar plate, it is generally assumed that each colony resulted from one, original cell.,
True
The term "sexually transmitted infection" is more accurate than "sexually transmitted disease" because a sexually transmitted pathogen may colonize host tissues without causing further damage to the host.
True
True or False: During replication, the point where separation of the DNA double helix occurs is called the replication fork.
True
True or False: In order to stain flagella so that they may be readily observed by light microscopy, it is usually necessary to increase their thickness.
True
True or False: Inflammation is a nonspecific defensive reaction to a tissue injury.
True
True or False: Light rays are refracted (bent) when they cross the interface between materials with different refractive indices.
True
True or False: Microorganisms show differential sensitivity to antimicrobial agents.
True
True or False: Some plasmid vectors have incorporated the regulatory sequences of the lactose operon so that the expression of the recombinant gene can be induced at the appropriate time.
True
True or False: The shorter urethra in females is one reason why urinary tract infections are more common in females than in males.
True
True or False: The term "sexually transmitted infection" is more accurate than "sexually transmitted disease" because a sexually transmitted pathogen may colonize host tissues without causing further damage to the host.
True
True or False: When counting isolated colonies on an agar plate, it is generally assumed that each colony resulted from one, original cell.
True
While exotoxin production is most generally associated with Gram-positive bacteria, some Gram-negative bacteria also produce exotoxins.
True
T/F: DNA replication results in two identical daughter molecules each consisting of one old (original) strand and one newly synthesized strand.
True- semiconservative replciation whereby one old strand is conserved or preserved in each new double helix.
Twitching motility involves _________
Type IV pili
Twitching motility involves _________.
Type IV pili
Which of the following methods of genetic recombination is common to both eukaryotic and bacterial cells?
Vertical gene transfer
Classify each of the following as either defining, or a component of, horizontal or vertical gene transfer.
Vertical gene transfer: crossing-over between sister chromosomes during meiosis, from parent to offspring, fusion of gametes Horizontal gene transfer: genes from one independent mature organism transferred to another mature organism, transformation, conjugation, transduction
What is an example of mold-lactic fermentation?
Viili
Match the microbe with an example of its importance to humans.
Viruses - cause serious diseases (smallpox, AIDS, Ebola fever)Prions- cause "mad cow disease" and Creutzfeld-Jacob diseaseFungi- include decomposers, associate with plant roots and help plants grow, produce antibiotics, help bread rise, and help make wineAlgae- photosynthetic, include unicellular and multicellular forms, and are the foundation of aquatic food chainsBacteria- beneficial microorganisms that fix nitrogen, make antibiotics as well as harmful microorganisms that cause disease (plague, strep thorat)
Why would it be beneficial for cells to wait until a critical population density is reached before expressing certain genes?
Without a certain density, it would be highly unlikely that the molecules produced by a cell in the group could find and bind to other cells of the population effectively.
The ribosomal RNA studies that led to the division of prokaryotic organisms into the Bacteria and the Archaea were begun by _________.
Woese
What is the WHO and where is it located?
World Health Organization (Geneva, Switzerland) the worldwide counterpart to the CDC
Dinoflagellates that exist endosymbiotically within a variety of marine invertebrates are called _________.
Zooxanthellae
One example of infectious disease transmission by a fomite is _______.
a child developing a cold after playing with a toy that harbored rhinovirus
The final outcome of most host-pathogen relationships depends on _________.
all the choices are correct
Which of the following is an example of gene regulation at the posttranslational level?
alteration of protein structure
What is an epidemic?
an abrupt increase in the frequency of a disease above the expected number
What is an outbreak?
an abrupt, unexpected occurrence of disease, usually in a limited segment of the population
A newly discovered microorganism has a circular chromosome that is complexed with histones but not enclosed within a membrane. The plasma membrane lipids include glycerol dietethers and diglycerol tetraethers. There are no mitochondria or chloroplasts but the cells do not contain 70s ribosomes. This microbe most likely is ________.,
an archaeon
What is the morbidity rate?
an incidence rate that measures the number of new cases in a specific time period per unit of population # new cases during a specific time/ # individuals in a population
What is a pandemic?
an increase in the occurrence of disease within a large population
The condition in the host that results from a microorganism growing and multiplying within or on the host is called ________.
an infection
What is a prokaryote?
an organism characterized by having a cell lacking a membrane-bound nucleus
All of the following are components of the mammalian host immune system EXCEPT ________.
antigens
Substances that are recognized as foreign and provoke immune responses are called ________.
antigens
Eukaryotic ribosomes differ from bacterial ribosomes in that the eukaryotic ribosomes _________.
are larger in size and require more initiation factors in order to be positioned properly on the mRNA
Eukaryotic ribosomes differ from the bacterial ribosomes in that the eukaryotic ribosomes_______.
are larger in size and require more initiation factors in order to be positioned properly on the mRNA
A vaccination is a good example of ________.
artificially acquired active immunity
A vaccination is a good example of_______.
artificially acquired active immunity
Botulinum antitoxin produced in a horse and given to a human suffering from botulism food poisoning is an example of ________.
artificially acquired passive immunity
Prior to staining, smears of microorganisms must be heat-fixed in order to______.
attach them firmly to the slide
Old cultures of bacteria that have lost their ability to cause disease are said to be _________.
attenuated
Which type of vaccine is better at boosting immune response?
attenuated vaccines
A(n) _________ is a special type of lysosome used by a cell to selectively digest and recycle cytoplasmic contents, such as mitochondria.
autophagosome
The term used to describe bacteria that are rod-shaped is _________.
bacillus
The term used to describe bacteria that are rod-shaped is_______.
bacillus
Lysozyme is an enzyme that lyses ________.
bacteria
A fundamental difference between bacterial and archaeal membranes is that _________.
bacterial membranes are always comprised of phospholipid bilayers, whereas archaeal membranes can be bilayers or monolayers
Bacterial replicons differ from eukaryotic and archaeal replicons in that _________.
bacterial replicons have no histones and a single origin of replication, whereas eukaryotes and archaea have multiple origins of replication, and their DNA is associated with histones
Which of the following inhibits bacterial growth but does not kill bacteria?
bacteriostatic agent
What is the U.S. Biological Weapons Defense Initiative?
based on developing, producing, and stockpiling specific antibody reagents that can be used to protect the population against biological warfare threats
Most bacterial and archaeal cells divide by _________.
binary fission
Most bacterial and archael cells divide by_________.
binary fission
On which of the following surfaces can biofilms form?
biotic or abiotic surface
Confocal microscopes exhibit improved contrast and resolution by _________.
blocking out stray light with an aperture located above the objective lens
Nucleotides are building blocks of_______.
both DNA and RNA
Protein function in modern cells as______.
both catalysts and structural elements
Proteins function in modern cells as _________.
both catalysts and structural elements
People with type AB blood have ______.
both type A and type B antigens on their cells
What is an example of mesophilic fermentation?
buttermilk, sour cream
A harmless PrP is converted into the infective PrP______.
by an abnormal PrP that binds to the normal protein and causes it to become misfolded
The Gram stain of a bacterial cell is based on the chemical properties of its _________.
cell wall
The gram stain of a bacterial cell is based on the chemical properties of its ______
cell wall
Match "cidal" and "static" with their definitions.
cidal- kills the microbestatic-keeps the microbe from dividing
The endoplasmic reticulum is composed of flattened sacs called _________.
cisternae
The term used to describe bacteria that have a spherical shape is _________
coccus
The term used to describe bacteria that have a spherical shape is _________.
coccus
When Nitrobacter utilizes nitrite produced from ammonia by Nitrosomonas to obtain energy by converting the nitrite to nitrate, the relationship between the two organisms is _________.
commensal
________ arises when different microbes within a population or community try to acquire the same resource.
competition
Horizontal gene transfer can occur via _________.
conjugation
In the Gram-staining procedure, the primary stain is ________.
crystal violet
In the Gram-staining procedure, the primary stain is _________.
crystal violet
The proper sequence of reagents in the Gram stain procedure is _________.
crystal violet, iodine, ethanol, safranin
Which of the following contribute(s) to the differences between the members of the Domain Archaea and the Domain Bacteria? a) Archaea lack muramic acid. b) Archaea differ from bacteria in their tRNA composition, ribosome structure, and antibiotic sensitivity. c) Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids. d) All of the choices are correct.
d) All are correct
The instrument that produces a bright image of the specimen against a dark background is called a(n) _________ microscope.
dark field
The instrument that produces a bright image of the specimen against a dark background is called a(n) ________ microscope.
dark-field
Order the steps of Pasteur's experiment.
designed to keep microbes from "falling out" of the air into the sterile broth within the flasks1. heat the broth to kill any microbes2. flasks sit for months without becoming full of thriving, living microbes3. when swan-neck flask was broken/dusk accumulated in the bend of the swan-neck was allowed back in the flask, it became contaminated
What are the aims of epidemiologists?
determining... -the causative agent -source/reservoir of agent -transmission mechanism -host and environmental factors that facilitate development of disease within a defined population -best control measures
In some circumstances, the strain is referred to as_________. ,
diauxic
In some circumstances, when two different carbon sources are available, growth will occur first using one carbon source, then after a short lag period, growth will resume using the second carbon source. This process is called __________ growth.
diauxic
The Gram-staining procedure is an example of _________.
differential staining
to determine if an outbreak, epidemic or pandemic is occurring, epidemiologists measure...
disease frequency at single time points and over time
What is a hyperendemic disease?
disease that increases gradually above the level of an endemic disease but not enough to classify as an epidemic
What is a sporadic disease?
disease that occurs occasionally, in irregular intervals
What is an endemic disease?
disease that occurs regularly at a low level of frequency and relatively regular intervals
What is an infectious disease?
disease that results from an infection by microbial agents
A new microbe has been discovered in the rumen of sheep. Microscopy shows no evidence of a nuclear membrane, and biochemical studies of the cell wall demonstrate the lack of peptidoglycan. Metabolic studies show that this microbe generates methane. This microbe would most likely be classified in _________.
domain Archaea
The total number of viable microorganisms remains constant in stationary phase because _________.
either there is a balance between cell division and cell death or there is a cessation of cell division even though the cells may remain metabolically active
The major site of cell membrane synthesis is the________.
endoplasmic reticulum
In the rumen, food is quickly attacked by cellulase _________
enzymes produced by microbes
What are common source epidemics?
epidemic that is caused by a single, common contaminated source characterized by a immediate increase in number of infected followed by a significant decrease in the number of infected
What are propagated epidemics?
epidemics caused by the introduction of an infected individual into a susceptible population, where the disease can be propagated to others characterized by gradual increase in sick individuals followed by a gradual decline over time
In the Gram-staining procedure, the decolorizer is _________.
ethanol or acetone
In a search for new antibiotics, a previously unknown organism has been recovered from the soil. It is nonmotile and is composed of long thread-like structures formed from nucleated cells. It is non-photosynthetic and absorbs its nutrients. This organism will most likely be classified among the _________
eukaryote(fungi)
In a search for new antibiotics, a previously unknown organism has been recovered from the soil. It is nonmotile and is composed of long thread-like structures formed from nucleated cells. It is non-photosynthetic and absorbs its nutrients. This organism will most likely be classified among the ________
eukaryotes (fungi)
Microorganisms are at their most uniform in terms of chemical and physiological properties during _________ phase.
exponential
Microorganisms are at their most uniform in terms of chemical and physiological properties during _______ phase.
exponential (log)
Scientists study microorganisms on Earth today to search for life forms elsewhere as well as to explore the origins of life on Earth. These microorganisms that are studied are referred to as _________.
extant
Scientists study microorganisms on Earth today to search for life forms elsewhere, as well as to explore the origins of life on Earth. These microorganisms that are studied are referred to as _________.
extant
Larger populations generally are killed as rapidly as smaller populations.
false
Initial attachment of microorganisms often involves ______.
flagella and is reversible
Tears protect the eyes by_______.
flushing and lysozyme
The function of the enzyme ligase is to_______.
form covalent bonds between cloned gene and plasmid
Define pandemic
increase in disease occurrence within a large population over a wide region (usually worldwide)
In general, as genome size of organisms increase, the metabolic and morphological complexity of the cell _________.
increases
When a pathogen is transferred from a water source to an animal before being transferred to a human, the animal is called a(n) ________ agent.
intermediate
What is fermentation?
involves the growth of microbes in large volumes for the production of industrially important products
In the Gram-staining procedure, the mordant is_________.
iodine
Sterilization involves_______all viable microorganisms.
killing OR removing
Sterilization involves _________ all viable microorganisms.
killing or removing
What are the major types of fermentation in food biology?
lactic, propionic, and alcoholic
What is the most common starter culture for cheese production?
lactobacillus species
The toxic component of lipopolysaccharide is called ________.
lipid A
Endotoxins include which of the following?
lipopolysaccharide
What is must?
liquid formed from crushing grapes
What are probiotics?
live microorganisms, which when administered in adequate amounts, confer a health benefit to the host
The lungs are protected from microorganisms by ________.
lysozyme in mucus phagocytic action of alveolar macrophages the mucociliary blanket [all of the choices are correct]
What is an example of industrial microbiology?
magnetosomes
define endemic disease
maintains a relatively steady low-level frequency at a moderately regular interval
The cytoplasmic membrane of bacteria_______.
major site of ATP synthesis in aerobes, retains the cytoplasm and its contents, acts as a selectively eprmeable barrier, allowing some molecules to pass while preventing the movement of others [all of the choices are correct]
What is mash?
malt mixed with water to hydrolyze starch to usable carbohydrates
define statistics
mathematics dealing with collection, organization and interpretation of numerical data
In the rumen, the carbohydrate fermentation end products include _________.
methane, carbon dioxide, acetate [all of the choices are correct]
Protein filaments with a diameter of 4-7 nm that play a role in cell movement and shape change are called _________.
microfilaments
A mutation that changes the amino acid sequence of the resulting protein by substitution is called a __________ mutation.
missense
Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and therefore, remain in the gene pool?
missense
What are the three numerical measures of disease frequency?
morbidity rate, prevalence rate, and mortality rate
What is antigenic shift?
more drastic changes that result in a completely different virus from a combination of strains
Chemotaxis is a process by which bacteria _________.
move toward an attractant or away from a repellent
What is antigenic drift?
natural mutation that results minor changes to the virus
When an individual's immune system responds to an appropriate antigenic stimulus during the course of daily activities, this is called ________.
naturally acquired active immunity
The DNA recombination method used during horizontal gene transfer between a bacterial cell and a eukaryotic cell is _________.
nonhomologous recombination
Define sporadic disease
occurs occasionally and at irregular intervals
What is an epidemiologist?
one who practices epidemiology
The site on the DNA to which a repressor protein binds is the __________.
operator
Which of the following gradients can form a biofilm?
oxygen, nutrient, and/or pH
The Golgi apparatus is responsible for the _________.
packaging of materials for excretion
The Golgi apparatus is responsible for the_______.
packaging of materials for excretion
Which of the following cells will be expected to contain the most active lysosomes?
phagocytosing white blood cell
The first surgical antiseptic to be used was _________
phenol
Distinguish between genotype and phenotype.
phenotype- how an organism appears (eye color, hair color, degree and ability of tase, quality of vision, natural resistance to a particular virus)genotype- DNA sequence coding for a particualr protein=specific visible trait- PTC taste response/lack, albinism, Huntington's disease/carrier
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you realize you forgot to apply the iodine in step 2. What would you expect to see if you observed the slide under the microscope after this omission?
pink gram positive and pink gram neg cells
If the decolorizer is left on too long in the Gram-staining procedure, Gram-positive organisms will be stained _________ and Gram-negative organisms will be stained _________.
pink; pink
Bacterial cells that are variable in shape are called______.
plemorphic
You are studying a newly discovered prokaryotic microorganism and are attempting to determine whether it will be classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except _________.
presence or absence of double-stranded circular DNA genome
RNA is a key intermediate molecule involved in the process that uses the information stored in DNA to ultimately produce _________
proteins
A newly discovered unicellular microbe has a nucleus containing linear chromosomes and is surrounded by a membrane. It has mitochondria, 80s ribosomes, and is covered by cilia. There is no cell wall external to the plasma membrane. This organism most likely would be a/an _________.
protozoan
A newly discovered unicellular microbe has a nucleus containing linear chromosomes and is surrounded by a membrane. It has mitochondria, 80s ribosomes, and is covered by cilia. There is no cell wall external to the plasma membrane. This organism most likely would be a/an _________.,
protozoan
In a lichen, the fungal partner _________.
provides water and minerals to the alga protects the alga from excess light intensities provides a substratum within which the alga grows [All of the choices are correct.]
After the primary stain has been added but before the decolorizer has been used, Gram-positive organisms are stained _________ and Gram-negative organisms are stained _________.
purple; purple
If the decolorizer is not left on long enough in the Gram-staining procedure, Gram-positive organisms will be stained _________ and Gram-negative organisms will be stained _________.
purple; purple
The nucleolus plays a major role in synthesis of _______.
rRNA
The process in which one or more nucleic acid molecules are rearranged or combined to produce a new nucleotide sequence is called _________.
recombination
Endocytic events________.
remove the membrane from the cell surface
Proteins are synthesized on structures called _________.
ribosomes
Which of the processes named here is the least likely to contribute to the evolution of genetic diversity of bacteria and archaea?
sexual reproduction
A __________ mutation does not alter the amino acid sequence of the resulting protein.
silent
"Sticky ends" are ________.
single-stranded DNA sequences that are generated by staggered cuts
To carry out Sanger sequencing a mixture is needed containing _________.
single-stranded DNA, DNA polymerase, complementary DNA primer, and four deoxyribonucleotides A,T,C,G
Which cellular shape is seen among members of domain Bacteria that is not found among the domain Archaea?
spiral or corkscrew shapes
Rigid bacteria with a helical cell shape are called _________.
spirilla
The concept that living organisms arise from nonliving material is called _________.
spontaneous generation
The destruction or removal of all viable organisms is called _________
sterilization
The destruction or removal of all viable organisms is called _________.
sterilization
When a dideozyribonucleotide is added to the daughter strand, replication of the strand__________.
stops
Any microorganism that spends a portion of its life associated with another organism of a different species is engaged in _________.
symbiosis
A general term used to describe groups based on mutual similarity or evolutionary relatedness is _________.
taxa
The science dealing with classification is called _________.
taxonomy
The reason coral reefs are among the most productive and successful ecosystems is due to _________.
the coral-dinoflagellate mutualistic relationship
The most important distinguishing feature of eukaryotes that is lacking in bacteria and archaea is _________.
the division of the cell into compartments that are bound by membranes
The most important distinguishing feature of eukaryotes that is lacking in bacteria and archaea is_______.
the division of the cell into compartments that are bound by membranes
What is the index case?
the first case in an epidemic
What is wort?
the liquid portion of mash
What is mortality rate?
the number of deaths from a given disease, as fraction of overall cases of that disease (number of deaths/population with disease)
What is morbidity rate?
the number of new cases of a disease during a particular period, as a fraction of the population size (number of cases during period/ population size)
What is a starter culture?
the preparation of living microorganisms that are deliberately used to assist the beginning of fermentation
If a frameshift mutation causes a stop codon to be inserted into the DNA sequence______.
the resulting protein will be too short and nonfunctional
Define epidemiology
the science that evaluates occurrence, determinants, distribution and control of health and disease in a defined human population
If you forgot to heat fix a smear before doing a Gram stain which of the following might occur?
the smear may not adhere to the slide
What is epidemiology?
the study of the origin, cause, distribution, and spread of disease
what is prevalence rate?
the total number of individuals infected at any one time, depends on both incidence rate and illness duration # of cases due to a given disease/size of total population
What is prevalence rate?
the total number of infected individuals in the population at any given time, as a share of the total population (number of cases/ population size)
What is bioremediation?
the use of microbes to "remedy" environmental problems, such as converting toxic materials to non-toxic materials
What is biodegradation?
the use of microbes to break organic matter into simpler compounds
Organisms that grow near deep-sea volcanic vents are likely to be _________.
thermophilic
At the E site______.
transfer RNA is released
Fever response can be triggered by an endogenous pyrogen called interleukin-1.
true
High concentrations of sugar or salt are used to control food spoilage because most microorganisms only grow well in habitats with high water activity.
true
True or False: rRNA signature sequences can be used to place microorganisms in the correct domain.
true
A person with type AB blood may receive ________.
type A, B, AB, and O blood
A person wtih type AB blood may receive________.
types A, B, AB, and O blood
What is a toxoid vaccine?
vaccine consisting of chemically or thermally modified toxins
What is an inactivated vaccine?
vaccine consisting of dead microbes or their fragments that can neither replicate or mutate to a more virulent form
What is an attenuated vaccine?
vaccine consisting of live microorganism that have undergone attenuations, which makes them less virulent
What is a subunit vaccine?
vaccine consisting of purified parts of the microorganism
What is a whole cell vaccine?
vaccine consisting of whole microorganisms
In the following list of scientists who was the first to observe and accurately describe microorganisms?
van Leeuwenhoek
A DNA molecule used to carry a foreign gene into a host organism is called a _________.
vector
The term used to describe bacteria that are shaped like curved rods is _________.
vibrio
What is an example of environmental microbiology?
waste water treatment
When does an infectious disease become communicable?
when it can be transmitted from person to person
What is wine enology?
wine production
What is an example of thermophilic fermentation?
yogurt
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells
you realize you forgot to apply the iodine in step 2. What would you expect to see if you observed the slide under the microscope after this omission?, pink gram-positive and pink gram-negative cells (iodine = mordant that binds with CV to form complex that prevents the dye from leaving the thick g+ cell wall)
describe public health surveillance
-collecting data and using it to compile advice to disseminate to health care providers and the public -protecting populations and improving the health of communities via education, promotion of healthy lifestyles, and prevention of disease or injury -take a methodical approach to identify issues... -review death certificates -field investigation of epidemics -investigation of actual cases
What are the three important statistical measures of disease frequency?
-morbidity rate -prevalence rate -mortality rate
define epidemic
-sudden increase in frequency above expected number
define outbreak
-sudden, unexpected occurrence of a disease - usually focal or in a limited segment of population
Order the stages of eukaryotic translation initiation.
1. Activation of mRNA by elongation initiaion factors2. Formation of the 43s complex3. 43S complex binds to 5' mRNA leader sequence4. 43S complex scans the mRNA and halts at the start codon5. 60S subunit attaches to 43S-mRNA complex to form complete 80s ribosome
Assess the diagrams and drag the picture labels to place each stage of eukaryotic translation initiation into the correct order.
1. Activation of mRNA by elongation initiation factors 2. Formation of the 43s complex 3. 43s complex binds to 5' mRNA leader sequence 4. 43s complex scans the mRNA and halts at the start codon 5. 60s subunit attaches to 43s-mRNA complex to form complete 80s ribosome
Order the stages that characterize progression of infectious disease.
1. Incubation period2. Prodromal stage3. Illness4. Height of Infection5. Death (of infectious disease causing organisms)6. Convalescent period
Order the phases of the bacterial growth curve.
1. Lag phase2. Exponential/Log phase3. Stationary phase4. Death phase5. Long-term stationary phase
What are three strategies that epidemiologists use to contain or eradicate disease?
1. Reduce or eliminate the source 2. Break the connection between the source and susceptible individuals 3. Reduce the number of susceptible individuals
Order the steps of binary fission.
1. a parent cell prepares for division by enlarging its cell wall, cell membrane, and overall volume2. two daughter cells are produced. some species separate completely as shown here, while others remain attached, forming chains, doublets, or other cellular arragements3. the septum is synthesized completely through the cell center, and the cell membrane patches itself so that there are two separate cell chambers4. the septum begins to grow inward as the chromosomes move toward opposite ends of the cell while other cytoplasmic components are distributed to the two developing cells. 5. A young cell at early phase of cycle
The proper sequence of reagents in the Gram stain procedure is_______.
1. crystal violet2. iodine (mordant)3. ethanol4. safranin
Which of the following must a pathogen possess in order for it to be successful at causing infectious disease?
ALL OF THE CHOICES ARE CORRECT*ability to damage the host*ability to be transported intially to the host*ability to adhere to, colonize, or invade the host
Bacteria within biofilms exchange_______.
ALL OF THE CHOICES ARE CORRECT*nutrients, quorum-sensing molecules, plasmids
Antigens_______.
ALL OF THE CHOICES ARE CORRECT*often protein or sugar in nature*can be described as self or foreign*any molecules that are recognized by the immune system
Cells may enter stationary phase because of________.
ALL OF THE CHOICES ARE CORRECT*the accumulation of toxic waste products*the depletion of an essential nutrient*a lack of available oxygen
The length of the lag phase of growth can vary depending on _________blank.
ALL OF THE CHOICES ARE CORRECT*the nature of the growth medium*the temperature*the condition of the microorganisms
The endosymbionts of ruminant animals are useful to their hosts in which of the following ways?
ALL OF THE CHOICES ARE CORRECT*the produce most of the vitamins needed by the ruminant*they digest the cellulose of plant cell walls*they convert glucose to organic acids
Under normal circumstances, which of the following is(are) normally pathogen-free environments in mammals?
ALL OF THE CHOICES ARE CORRECT*ureters*urinary bladder*kidneys
Which of the following is a reason for the occurrence of a lag phase in a bacterial growth curve?
ALL OF THESE ARE POTENTIAL REASONS *The cells may be old and depleted of ATP, essential cofactors, and ribosomes that must be synthesized before growth can begin.*The organisms may have been injured and require time to recover.*The cells may be old and depleted of ATP, essential cofactors, and ribosomes that must be synthesized before growth can begin.
Which of the following types of immunity primarily relies on interactions between antigens and antibodies?
Adaptive immunity
Drag the labels to their corresponding mechanism of transmission.
Airborne transmission: sneezing, coughing, droplet nuclei, dust Contact transmission: touching, kissing, sex Vehicle transmission: surgical instruments, shared cups, fomites Vector-borne transmission: ticks, animals, mosquitoes, arthropods, fleas
Which of the following are characteristics of hydrogenosomes that distinguish them from mitochondria?
All of the above
Bacteria within biofilms exchange _________.
All of the choices are correct.
Which of the following is a function of the mitochondrion? a) Tricarboxylic acid cycle enzyme reactions b) Electron transport c) All of the choices are correct. d) ATP synthesis
All of the choices are correct.
Antigens __________.
All of the choices are correct. -are often protein or sugar in nature -are any molecules that are recognized by the immune system -can be described as self or foreign
According to the endosymbiosis hypothesis _________.
All of the choices are correct: -the mitochondrion evolved from the same endosymbiont as the hydrogenosome -the first endosymbiotic event involved an anaerobic bacterium -the first endosymbiont was a fermentative organism
The characteristics of a pathogen that determine its virulence include which of the following?
All the choices are correct. Invasiveness Infectivity Pathogenicity
In eukaryotes, the initiator tRNA for translation is _________.
Met-tRNAiMet, which is also used by archaea
Protein filaments with a diameter of 4-7 nm that play a role in cell movement and shape change are called _________.
Microfilaments
Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and, therefore, remain in the gene pool?
Missense
The transfer of antibodies in breast milk is a good example of ________.
Naturally acquired passive immunity
Several cases of an emerging infectious disease are reported in workers at a research station that borders a tropical rainforest region. The pathogen is identified as a species of bacteria carried by nematodes that infect mosquitos, and disease transmission occurs in a human host following a mosquito bite. Which organisms should be targeted in the treatment of infected patients?
Nematode and bacteria
Prions cause_____diseases.
Neurodegenerative
Which of the following is not a characteristic of lipid A?
Neurotoxicity
A __________ mutation is one that causes premature termination of the synthesis of the protein product.
Nonsense
Match each mutation with its appropriate description.
Nonsense mutation: A mutation that changes a codon encoding an amino acid to a stop codon, resulting in premature termination of polypeptide synthesis Missense mutation: A mutation that results in changing a codon such that a different amino acid is inserted Silent mutation: A mutation that changes a codon into a different codon, but both codons specify the same amino acid; this causes no change in the resulting polypeptide Frameshift mutation: A mutation resulting from an insertion or deletion of bases that causes a change in the reading frame of the mRNA
Which of the following is considered ot be a biological defense mechanism?
Normal microbiota
DNA in cells can encode thousands of different proteins. Why do cells require mechanisms to regulate expression of the genes that code for these proteins?
Not all proteins are needed at all times, or in equal amounts. Regulating their expression saves energy and time.
The concept that human and animal diseases are caused by microorganisms is called the _________.
germ theory
The concept that human and animal diseases are caused by microorganisms is called the______.
germ theory
What is malt?
germinated barley grains with activated enzymes
Which of the following organelles is involved in the modification packaging, and secretion of materials?
golgi apparatus
Which of the following organelles is involved in the modification, packaging, and secretion of materials?
golgi apparatus
define hyperendemic disease
gradually increase in occurrence frequency above endemic level but not epidemic level
The primer used in Snager sequencing_______.
has a nucleotide sequence complementary to the 3' end of the region to be copied
A person ingests a pathogen, but fails to develop signs or symptoms of disease. The pathogen likely has a infectious dose and/or a replication rate.
high; low
Transfer of genes from one mature independent organism to another is called _________.
horizontal gene transfer
The most likely source of the Taq polymerase used in PCR is a bacterium that lives in _________.
hot vents