Microbiology: Module 2 - Homework Flashcards
A) have a slightly curved rod shape.
B) are flexible.
C) reproduce by snapping division.
D) are roughly spherical.
E) vary in size and shape.
Bergey's Manual contains
A) classification schemes for prokaryotes.
B) treatments for bacterial diseases.
C) recipes for bacterial growth media.
D) genetic sequences of prokaryotes.
E) rules for naming new bacterial species
When conditions become inhospitable, members of the genus Clostridium
produce an internal durable, dormant form by the process of
d. binary fission.
The Gram-positive obligate anaerobe ________ causes a severe
a. Clostridium difficile
b. Bacillus anthracis
c. Clostridium perfringens
d. Clostridium botulinum
The ________ are autotrophs which live in anaerobic environments
thought to be similar to conditions on the early Earth, and may have
diverged from other bacteria far back in time.
a. deeply branching bacteria
A large number of Gram-negative human pathogens are members of
A field biologist finds what might be a new species of prokaryote in sewage sludge. It is an obligate anaerobe that metabolizes organic acids and requires hydrogen gas. It lacks a peptidoglycan cell wall. The new find may be a____.
The anaerobic Clostridium species are troublesome pathogens largely
because of their capacity for
A) endospore production.
B) rapid reproduction.
C) oxygen production.
D) biofilm production.
E) high salt tolerance.
Members of the Streptomyces are environmentally important because they can degrade a wide range of compounds including lignin from trees, chitin and keratin from animals, and latex.
Mycoplasmas are named for the large quantities of mycolic acid in their cell walls.
Myxobacteria exhibit traits, such as cooperation and differentiation, that are not normally observed in prokaryotes.
Members of the genus Chlamydia are
B) intracellular parasites.
C) classified with the deeply branching bacteria.
E) Gram-positive bacteria.
The Gram-positive coccus ____ grows in irregular clusters, and is frequently found in the human nasal cavity. When it invades other parts of the body it can cause serious disease.
a. Clostridium perfringens
b. Staphylococcus aureus
c. Escherichia coli
d. Bacillus thuringiensis
e. Helicobacter pylori
A soil sample dilution spread on a plate containing carbohydrate-based medium yields a wide variety of colonies. One colony has no other bacterial colonies growing near it. Further investigation reveals the bacteria in the colony are Gram-positive and filamentous. The bacteria in the colony may be a member of the genus.
Sister chromatids separate and move toward the poles of the cell during ____ of mitosis.
Which of the following statements regarding meiosis is most
a. homologous (non sister) chromatids separate during anaphase II
b. diploid cells produce haploid daughter cells
c. haploid cells produce diploid cells
d. meiosis has the same number of stages and mitosis
e. crossing over occurs during metaphase I
Which of the following pairs is mismatched
a. entamoeba: pseudopodia
b. euglena: flagellum
c. plasmodium: merozoites
d. paramecium: two nuclei
e. toxoplasma: cilia
Which of the following types of protozoa contributes to limestone
formation in their fossilized state?
Which of the following is a cell type associated with sexual
reproduction in fungi?
Ciliates often have two kinds of nuclei that have different functions.
Algae can have different types of photosynthetic pigments that allow them to photosynthesize at various depths in water.
Myxamoebae act like protozoan amoebae only in the absence of water.
Current classification of the algae is based on morphologic characteristics.
The classification Protozoa is not an accepted taxon because it includes members of multiple kingdoms.
In what way do algae differ from plans?
a. All cells in their sexual reproductive structures become gametes.
b. They carry out photosynthesis with pigments other than chlorophyll a.
c. All algae are unicellular.
d. They carry out anoxygenic photosynthesis.
e. They have cell walls composed of carbohydrate.
Which of the following is associated with meiosis, but NOT with mitosis?
a. a zygote
b. a chromatid
c. a tetrad
d. a spindle
e. a centromere
Mites are responsible for the spread of
a. Lyme disease
b. Disease caused by Apicomplexans
d. Diseases caused by Rickettsias
e. Helminth diseases
Multiple mitoses followed by a single cytokinetic event is known as
d. coenocytic division
Which of the following is an accurate description of a
A) the nucleic acid of a viral pathogen
B) an infectious particle of protein and nucleic acid outside a host cell
C) a population of infectious particles
D) the protein portion of a viral particle
E) the nucleic acid of a viral pathogen inside a host cell
Which of the following is present in cells only during virus
D) DNA-RNA heteroduplex
E) triplet RNA
Host specificity of a virus is due to
A) particular genes that it shares with the infected cell.
B) the presence of an envelope.
C) differences in size between the virus and the host cell.
D) the presence or absence of a cell wall on the host cell.
E) interactions between viral and cellular surface molecules.
How are fungal viruses different from viruses that infect other
A) They have no extracellular state.
B) They have only DNA for genetic material.
C) They have no capsid.
D) They have no intracellular state.
E) They cannot pass through a filter.
Which of the following may occur in a lysogenic infection, but not a
A) The prophage/provirus alters gene expression in the host cell.
B) The viral DNA integrates (inserts) into the host cell DNA.
C) The prophage/provirus is replicated with the host DNA.
D) The provirus/prophage directs the synthesis of viral proteins.
E) The inserted viral DNA may leave the host DNA.
Which of the following statements regarding virus taxonomy is true?
A) Some virus family names are derived from the name of an important member of the family.
B) The species epithet is a Latin descriptor of the virion structure.
C) Virus classes are well established.
D) Viruses are classified on the basis of the taxonomy of their host organisms. E) Virus classes are based on the domain of the host organism.
Why is lysogeny advantageous to a bacteriophage?
A) It allows the bacteriophage to destroy the host cellʹs DNA.
B) It speeds up the viral infection cycle.
C) The genetic material of the bacteriophage is amplified many times over that seen in a lytic
D) It enables the bacteriophage to take over the cell.
E) It allows the bacteriophage to infect cells it would not normally infect.
Zones of clearing in cell cultures that are the result of virus
infection are called plaques. Sometimes ʺcloudy plaquesʺ are seen on
bacterial cultures infected with bacteriophage. What type of
infection might cause this appearance?
Plaque assays are used for
A) counting the number of latent phages in a cell.
B) the study of prions.
C) determine the density of phage in a culture.
D) cultivating viruses that cannot be grown any other way.
E) evaluating the cancer-causing ability of a virus.
Retroviruses require the activity of ____ to complete their infection
B) RNA-dependent RNA polymerase
C) RNA-dependent RNA transcriptase
D) reverse transcriptase
E) viral RNA polymerase
The development of a cancerous cell is said to require "multiple hits." This means
a. multiple oncogenic viruses infect the cell at the same time
b. multiple cell cycle regulators are inactivated at once
c. a series of separate events over time lead to the loss of cell cycle regulation
d. the cell must be infected with several different types of viruses to be transformed
e. several protoncogenes are activated at the same time
Which of the following agents is capable of inducing conversion of a prophage to the lytic cylce?
a. presence of +ssRNA
c. UV light
d. both UV light and X-rays
e. both UV light and the presence of +ssRNA
Why are diploid cells preferred over continuous cell cultures?
a. Diploid cells last far longer than continuous culture cells.
b. Continuous cell cultures are expensive to maintain.
c. Results from continuous culture cells do not apply to disease in whole organisms.
d. Diploid cells are more nearly like cells of whole organisms than continuous culture cells.
e. Diploid cells have undergone changes in their chromosome structure that make them more stable.
A microbe recovered from an environmental sample grows on a medium composed of agar and a mix of salts. The agar is not digested during incubation. The growth rate increases in high CO2 conditions. The organism is likely a(n)
e. the answer cannot be determined from the information provided.
Prokaryotes living in the ocean around volcanic vents use the volcanic gasses carbon dioxide (CO2) and hydrogen sulfide (H2S) to fuel their metabolism. They are therefore
A microbe that grows only at the bottom of a tube of thioglycollate
medium is probably a(n)
A) obligate aerobe.
B) facultative anaerobe.
C) aerotolerant anaerobe.
E) obligate anaerobe.
You open a jar that has been in the refrigerator for a couple of weeks and find the contents do not look or smell right. What type of microbe has been growing in your refrigerator?
A microbiologist inoculates a growth medium with 100 bacterial
cells/ml. If the generation time of the species is 1 hour, and there
is no lag phase, how long will it be before the culture contains more
than 10,000 cells/ml?
A) 24 hours
B) 7 hours
C) 2 hours
D) 3 hours
E) 10 hours
Students in a microbiology lab are provided plates of medium to use in their bacterial culturing. The growth of organisms that can metabolize mannose sugar will result in the agar turning yellow, while the agar color remains unchanged if the mannose is not metabolized. The plates contain a ________ medium.
A 100 μl sample containing 1000 bacterial cells/μl in log phase growth is added to 9.9 ml of fresh culture medium broth. Assuming no nutrients are in limited supply, and a generation time of 30 minutes, how many bacteria will be present in the entire broth culture after six hours?
a. 6.0 x 105
b. 2.56 x 107
c. 1.2 x 106
d. 4.396 x 108
e. 6.0 x 106
The best method for preserving bacterial cells in storage for decades is
a. storing them in shrink-wrap
b. drying under anaerobic conditions
e. deep freezing
A Petroff-Hauser counting chamber is a(n)
a. device that measures the amount of light that passes through a culture
b. device used to count numbers of bacterial colonies on a Petri plate
c. glass slide containing an etched grid for counting microbes directly using a microscope
d. device that counts cells as they interrupt an electrical current
e. apparatus that traps bacterial cells on a membrane filter where they can be counted
Which of the following statements concerning reduction reactions is
a. A molecule gains a hydrogen atom.
b. They frequently involve electron carrier molecules.
c. An electron acceptor gains an electron.
d. An electron acceptor becomes more positively charged.
e. They are coupled with oxidation reactions.
Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as
a. allosteric inhibition
b. noncompetitive inhibition
c. feedback inhibition
d. competitive inhibition
e. excitatory allosteric control
Which of the following statements concerning glycolysis is
a. Glycolysis is an alternative to fermentation.
b. Glycolysis occurs in the cell membranes of bacteria.
c. Glycolysis both requires the input of ATP and produces ATP.
d. Ribulose 5-phosphate is an intermediate of glycolysis.
e. Glycolysis produces ATP by oxidative phosphorylation.
Which of the following is (are) common to chemiosmosis and the light-dependent reactions of photosynthesis?
a. electron transport only
b. a proton gradient only
c. reduction of NADP+ only
d. both electron transport and a proton gradient
e. electron transport, a proton gradient, and reduction of NADP+
What is the major product of the Calvin-Benson cycle that can then be
used to form glucose?
D) glyceraldehyde 3-phosphate
Which of the following statements is MOST accurate concerning metabolism?
a. metabolism is all the chemical reactions of an organism, both anabolic, and catabolic
b. metabolism is the assembly of small molecules into macromolecules
c. metabolism is the production and expenditure of chemical energy
d. metabolism is the digestion of nutrients to release energy
e. metabolism is the assembly of macromolecules into cellular structure
If a cell reverses the process of beta-oxidation, which of the
following molecules will it make?
B) amino acids
C) fatty acids
Which of the following is a TRUE statement concerning the structure
and function of enzymes?
A) All enzymes bind to cofactors necessary for their function.
B) An apoenzyme is a combination of a cofactor bound to a holoenzyme.
C) The higher the temperature, the faster an enzyme will work.
D) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme.
E) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
Isomerases catalyze reactions in which
A) atoms in biomolecules are rearranged.
B) groups are transferred from one molecule to another.
C) biomolecules are broken down into their component parts.
D) biomolecules are assembled from smaller molecules.
E) biomolecules are oxidized or reduced.