Test
Microorganisms MCQ's 2011
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Preguntas del test (49)
1Modes of obtaining nutrition, used by at least some bacteria, include all of the following EXCEPT:
- AChemolithoautrophy
- BPhotolithoautrophy
- CChemoheteroautrophy
- DChemoorganoheterotrophy
2Which of the following forms of oxygen are generally toxic to living organisms?
- ASuperoxide anion
- BHydrogen peroxide
- CHydroxyl radical
- DAll of the above
3Carrier mediated transport is necessary when:
- ADiffusion will not allow adequate amounts of a substance to enter the cell
- BMovement into the cell is against a concentration gradient
- CThe level of nutrients in nature is very low
- DAll of the above
4The size (as determined by the sedimentation factor) of the most useful RNA molecule for prokaryotic evolutionary studies is:
- A5S
- B16S
- C18S
- D23S
5Which of these environmental factors influence microbial growth?
- ApH
- BWater potential
- COxygen
- DAll of the above
6The signature sequence is used extensively in the:
- APhylogenetic probe
- BReclassification of misclassified organisms
- CDefining of a specific group within a domain
- DAll of the above
7With regards to the bacterial genome which statement is the correct one?
- ABacterial genome is triploid
- BBacterial genome is mostly haploid
- CBacterial genome is mostly diploid
- DBacterial genome is haploid
8With regards to bacterial plasmids which statement is the correct one?
- AA plasmid is a regulatory gene
- BA plasmid is a short RNA molecule
- CA plasmid is an extra chromosomal DNA molecule
- DA plasmid is a non coding region found in some bacterial genomes
9All viruses:
- AHave a genome that is a single molecule of nucleic acid
- BAre enveloped
- CEncode more proteins in their genomes than those contained in the mature virus particle
- DHave capsids that are icosahedral in shape
10Poliovirus:
- AHas a double-stranded DNA genome
- BHas a capsid that is composed of 240 copies of a single protein
- CReplicates primarily in the upper respiratory tract
- DBelongs to the enterovirus genus of the picornavirus family
11Which of the following is NOT an alternative name for cutaneous fungal infections of humans:
- ASuperficial mycoses
- BDermatophytes
- CMycetoma
- DRingworms
12Which of the following is NOT part of the plant disease triangle:
- ASusceptible host
- BClimate change
- CActive pathogen
- DSuitable environment
13The Bacille-Calmette-Guérin (BCG) vaccine is:
- AHeat-killed Mycobacterium tuberculosis
- BAttenuated live Mycobacterium tuberculosis
- CMycobacterium bovis
- DAttenuated live Mycobacterium bovis
14Which of the following is a bacterial infection?
- AWhooping cough
- BPolio
- CAcquired immunodeficiency syndrome
- DMalaria
15Pasteur is attributed with which one of the following discoveries?
- AWas the first to see microorganisms under a microscope
- BFirst to discover and use agar
- CThat there could be life without air
- DThe first chemical antibiotics
16The length of a typical E. coli cell is approximately?
- A20 μm
- B2 μm
- C200 nm
- D20 nm
17With respect to differences between members of the archaeal and bacterial domains/kingdoms, which is the correct statement?
- ABoth have peptidoglycan in their cell walls
- BOnly some Archaea are capable of methanogenesis
- CArchaea are sensitive to β-lactam antibiotics
- DBacteria have similar RNA polymerase to that of Archaea
18Which statement is correct with respect to the E.coli chromosome?
- AIt is negatively supercoiled
- BIt is positively supercoiled
- CThere are typically several origins of replication
- DIt consists of over 50 million base pairs
19A culture of E. coli is diluted by a factor of 10-6 and, after plating out 100 μl on an agar plate, 93 colonies grew after incubation at 37oC overnight. The original culture therefore contained how many viable E. coli cells per ml?
- A9.3 x 10(7)
- B9.3 x 10(8)
- C9.3 x 10(6)
- D9.3 x 10(5)
20Bacterial flagella bring about cell motion by which mechanism?
- AWave-like movement of the flagellum
- BRotation of the cell
- CRotation of the flagellum in one direction only
- DRotation of the flagellum that is reversible
21In the Earth’s biosphere most fungal biomass and diversity is found:
- AIn the oceans
- BIn soils
- CUnder glaciers
- DIn the atmosphere
22Fungal growth and cell division is NOT normally accompanied by:
- ABiomass acquisition
- BReduced vitality
- CNucleic-acid replication
- DEnhanced ability to compete with other microbial species
23One factor that is NOT used to prevent or reduce fungal spoilage of processed foods is:
- AAddition of benzene
- BLow water-activity
- CRefrigeration
- DHeat-sterilization
24Saprophytic activity is essential for the health of the biosphere because:
- AIt facilitates nutrient cycling and waste degradation
- BIt kills host organisms and thereby averts overpopulation
- CIt facilitates species evolution via endosymbiosis
- DIt involves mineralization of inorganic rocks in the lithosphere
25The cardinal temperatures are the:
- AMinimum temperatures
- BOptimum temperatures
- CMaximum temperatures
- DMinimum, optimum, and maximum temperatures taken together
26Carl Woese of the University of Illinois and his collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?
- AMicroscopic examination of the staining characteristics of the cell wall
- BMetabolic characteristics such as the production of methane gas
- CEcological characteristics such as the ability to survive extreme temperatures
- DMolecular characteristics such as ribosomal RNA sequences
27Which prokaryotes should be expected to be most strongly resistant to plasmolysis in hypertonic environments?
- AExtreme halophiles
- BExtreme thermophiles
- CMethanogens
- DNitrogen-fixing bacteria that live in root nodules
28Photoautotophs use:
- ALight as an energy source and CO2 as a carbon source
- BLight as an energy and methane as a carbon source
- CCO2 as both an energy source and a carbon source
- DAll of the above
29Addition of blood to a culture medium only allows the haemolytic bacteria that grow on the plate to be picked out. This is an example of a:
- ASelective medium
- BDifferential medium
- CComplex medium
- DSynthetic medium
30A microbe growing in a functioning refrigerator is probably a:
- APsychrophile
- BMesophile
- CThermophile
- DHyperthermophile
31Which one of the following sentences correctly describes the science of Metagenomics?
- AMetagenomics is a genome- level study of the whole microbial community
- BMetagenomics is a genomics of industrially and medically important bacteria
- CMetagenomics is a study of genes’ expression
- DMetagenomics is a comparative analysis of the sequenced microbial genomes
32Genetic recombination is a:
- AChange of DNA structure caused by radiation
- BAmplification of DNA molecules followed by cell division
- CPhysical exchange between DNA molecules
- DProcess resulting in protein synthesis
33All viruses:
- AEnter cells by receptor-mediated endocytosis
- BReplicate their genomes in the nucleus of the cell
- CReplicate their genomes in the cytoplasm of the cell
- DSurround their progeny genomes with capsid proteins inside infected cells
34Tobacco mosaic virus has:
- AAn icosahedral capsid
- BA helical capsid
- CMultiple copies of each of four proteins making up the capsid
- DMultiple copies of two proteins making up the capsid
35Anthrophilic dermatophytes (fungi causing cutaneous infections of humans) are primarily associated with:
- ASoil
- BAnimals
- CPlants
- DHumans
36Secondary symptoms of infections of plants by pathogens:
- AOccur at some distance from the point of infection
- BNormally occur close to the site of active infection
- CAre an ideal place to isolate the causal organism
- DNever occur at the same time as primary symptoms
37Which one of the following infectious diseases has been eradicated from the human population?
- APlague
- BLeprosy
- CSmall pox
- DPolio
38Which of the following is a host component important in specific immune recognition of extracellular microbes?
- AAntigen
- BAntibody
- CPhagocyte
- DLipopolysaccharide
39With regard to the differences between bacterial and eukaryotic cells which statement is the CORRECT one?
- ABacterial cells do not contain mitochondria
- BBacterial cells are always larger than eukaryote cells
- CBacteria do not contain a chromosome
- DEukaryotic cells are sensitive to β-lactam antibiotics
40Koch’s postulates most CORRECTLY relate to which one of the following statements?
- AThe isolation of a bacterium in culture from an infection alone indicates that it caused the disease
- BIsolation and cultivation of a microorganism from a diseased animal, then inoculation into another healthy animal to cause the same disease, followed by re-isolation of the same microorganism, indicates that it is the cause of the disease
- CThe observation of virus particles in tissue from a human with disease indicates that it has caused the disease
- DInoculation of a bacterium into an animal and observation of disease alone indicates that it is the cause of the disease observed
41Which statement is CORRECT with respect to Lipopolysaccharide (LPS)?
- ALPS is found in Gram positive cells
- BLPS is found in Gram negative cells in the cytoplasmic membrane
- CLPS is found in the outer-membrane of Gram negative cells.
- DLPS is found inside all bacterial cells
42A culture of E. coli is diluted by a factor of 10-6 and, after plating out 100 μl on an agar plate, 57 colonies grew after incubation at 37oC overnight. The original culture therefore contained how many viable E. coli cells per ml?
- A5.7 x 10(7)
- B5.7 x 10(8)
- C5.7 x 10(6)
- D5.7 x 10(5)
43With respect to differences between members of the archaeal and bacterial domains/kingdoms, which is the CORRECT statement?
- AWith respect to differences between members of the archaeal and bacterial domains/kingdoms, which is the CORRECT statement?
- BOnly some Archaea are capable of methanogenesis
- CArchaea are sensitive to β-lactam antibiotics
- DBacteria have similar RNA polymerase to that of Archaea
44Which statement is CORRECT with respect to peptidoglycan?
- AThere are multiple molecules of peptidoglycan in bacterial cell walls
- BOnly Gram positive cells possess peptidoglycan
- CThere is only a single molecule of peptidoglycan in a bacterial cell wall
- DPeptidoglycan is only found in Gram negative cell walls
45The primary reason that health professionals recommend that new-born babies are not washed is:
- ASo that they can be inoculated with symbiotic yeast species
- BTo avoid imbalances in the microbial ecology of indigenous flora
- CTo avoid accidental contamination with fungal spores
- DSo that clinical microbiologists can study the impact on the current generation
46Post-genomic techniques include:
- AProteomics
- BUse of restriction enzymes
- CGene sequencing
- DStudies of signal-transduction pathways
47Systems biology approaches to the study of fungal cells do NOT necessarily involve:
- AGeneration of data from biological experiments
- BMathematical quantification of changes in cell components
- CCreation of a model of the cellular system in silico
- DCreation of a conceptual model based on philosophical techniques
48Which of these statements is untrue?
- ASome species of yeasts are highly tolerant to ethanol stress
- BSome species of fungi are extremely xerophilic
- CMany fungi are more tolerant to water stress than any bacterial species
- DFungi can grow over the entire pH range from 0 to 14
49An extremophilic microbe is one which:
- ACan survive dry conditions
- BCan grow only when there is a mixture of stress parameters (e.g. high temperatures and low pH)
- CCan grow optimally under extreme conditions
- DBecomes dormant under extreme conditions
Información
- Descripción
- Papers covered; August 2011 May 2011
- Autor
- tj.sloan
- Idioma
- English
- Visitas
- 74
- Valoración
- Aún sin valoraciones Valora este test