Deck 10: Classification of Microorganisms

Question 1

Fossil evidence indicates that prokaryotic cells first existed on the Earth at least

A)350 years ago.
B)3500 years ago.
C)35000 years ago.
D)3)5 billion years ago.
E)3)5 × 10¹² years ago.

Answer 1

D

Question 2

Figure 10.1

In Figure 10.1,the closest ancestor for both species "a." and species "b." would be which of the following?

A)1
B)2
C)3
D)4
E)5

Answer 2

E

Question 3

Which one of the following provides taxonomic information that includes the information obtained in each of the other options listed?

A)nucleic acid hybridization
B)nucleic acid-base composition
C)amino acid sequencing
D)biochemical tests
E)cladogram

Answer 3

E

Question 4

If two organisms have similar rRNA sequences,you can conclude that they

A)live in the same place.
B)evolved from a common ancestor.
C)will have different G-C ratios.
D)will both ferment lactose.
E)mated with each other.

Question 5

Which of the following statements about archaea is FALSE?

A)They are prokaryotes.
B)They lack peptidoglycan in their cell walls.
C)Some are thermoacidophiles;others are extreme halophiles.
D)They evolved before bacteria.
E)Some produce methane from carbon dioxide and hydrogen.

Question 6

A genus can best be defined as

A)a taxon composed of families.
B)a taxon composed of one or more species and a classification level lying below family.
C)a taxon belonging to a species.
D)a taxon comprised of classes.
E)the most specific taxon.

Question 7

Which of the following statements about the members of the Kingdom Animalia is FALSE?

A)They are multicellular.
B)They are composed of eukaryotic cells.
C)They undergo photosynthesis.
D)They ingest nutrients through a mouth.
E)They are heterotrophs.

Question 8

Figure 10.1

In Figure 10.1,species "c." is most closely related to which of the following?

A)a
B)b
C)c
D)d
E)e

Question 9

What is the outstanding characteristic of the Kingdom Fungi?

A)All members are photosynthetic.
B)Members absorb dissolved organic matter.
C)Members absorb dissolved inorganic matter.
D)All members are microscopic.
E)All members are macroscopic.

Question 10

A bacterial species differs from a species of eukaryotic organisms in that a bacterial species

A)does not breed with other species.
B)has a limited geographical distribution.
C)can be distinguished from other bacterial species.
D)is a population of cells with similar characteristics.
E)breeds with its own species.

Question 11

In the scientific name Enterobacter aerogenes,Enterobacter is the

A)specific epithet.
B)genus.
C)family.
D)order.
E)kingdom.

Question 12

Which one of the following statements is a reason for NOT classifying viruses in one of the threedomains of life (Bacteria,Archaea,Eukarya)rather than in a fourth separate domain?

A)Some viruses can incorporate their genome into a host's genome.
B)Viruses direct anabolic pathways of host cells.
C)Viruses are obligate parasites.
D)Viruses are not composed of cells.

Question 13

A biochemical test,in the microbiology world,is used to determine

A)staining characteristics.
B)amino acid sequences of enzymes.
C)nucleic acid-base composition of DNA sequences.
D)capability of a microbe to perform a specific enzymatic activity.
E)All of the answers are correct.

Question 14

Which of the following is NOT based on nucleic-acid hybridization?

A)DNA chip
B)FISH
C)PCR
D)Southern blotting
E)Western blotting

Question 15

The phylogenetic classification of bacteria is based on

A)cell morphology.
B)Gram reaction.
C)rRNA sequences.
D)habitat.
E)diseases.

Question 16

Which of the following statements about members of the Kingdom Plantae is FALSE?

A)They are multicellular.
B)They are composed of eukaryotic cells.
C)They undergo photosynthesis.
D)They use organic carbon sources.
E)They synthesize organic molecules.

Question 17

Which of the following characterizes the Domain Bacteria?

A)prokaryotic cells;ether linkages in phospholipids
B)eukaryotic cells;ester linkages in phospholipids
C)prokaryotic cells;ester linkages in phospholipids
D)complex cellular structures
E)multicellular

Question 18

________ are a diverse group of eukaryotic organisms that are similar in rRNA sequences,but quite different from each other in motility types and ecology.They have been used previously as a "catch-all" for organisms that couldn't be easily classified into other groups.

A)Protists
B)Fungi
C)Plants
D)Methanogens

Question 19

The arrangement of organisms into taxa

A)shows degrees of relatedness between organisms.
B)shows relationships to common ancestors.
C)was designed by Charles Darwin.
D)is arbitrary.
E)is based on evolution.

Question 20

Which of the following is the best evidence for a three-domain system?

A)Nucleotide sequences in ribosomal RNA vary between all three domains.
B)There are three distinctly different sets of metabolic reactions.
C)There are three distinctly different Gram reactions.
D)Some bacteria live in extreme environments.
E)There are three distinctly different types of nuclei.

Question 21

Table 10.1

In Table 10.1,which feature(s)is (are)found only in prokaryotes?

A)1,2,3
B)4,6
C)2
D)1
E)2,4,5

Question 22

A clone is

A)genetically identical cells derived from a single cell.
B)a genetically engineered cell.
C)a taxon composed of species.
D)a mound of cells on an agar medium.

Question 23

Phage typing is based on the fact that

A)bacteria are destroyed by viruses.
B)viruses cause disease.
C)bacterial viruses attack only members of a specific species.
D)Staphylococcus causes infections.
E)phages and bacteria are related.

Question 24

Organism A has 70 moles % G+C,and organism B has 40 moles % G+C.Which of the following can be concluded from these data?

A)The two organisms are related.
B)The two organisms are unrelated.
C)The organisms make entirely different enzymes.
D)Their nucleic acids will completely hybridize.

Question 25

Bacteria and Archaea are similar in which of the following?

A)peptidoglycan cell walls
B)methionine as the start signal for protein synthesis
C)sensitivity to antibiotics
D)considered prokaryotic cells
E)plasma membrane ester linkage

Question 26

Figure 10.2 A nucleic acid hybridization experiment produced the following results.

In Figure 10.2,which figure shows the most closely related organisms?

A)a
B)b
C)c
D)d
E)e

Question 27

All of the following statements are reasons why fluorescent in situ hybridization (FISH)has become a valuable tool for environmental microbiologists EXCEPT

A)it allows for detection of uncultured microbes.
B)it demonstrates the diversity of microbes in an environment.
C)it allows observation of microbes in their natural environment in association with other microbes.
D)it allows one to obtain pure cultures of microbes.

Question 28

Into which group would you place a photosynthetic cell that lacks a nucleus?

A)Animalia
B)Bacteria
C)Fungi
D)Plantae
E)Protista

Question 29

Table 10.1

In Table 10.1,which features are found in nearly all eukarya?

A)2,3,5
B)1,4,6
C)3,5
D)2,3
E)1,2,5

Question 30

You discovered a unicellular organism that lacks a nucleus and peptidoglycan.You suspect the organism is in the group

A)Animalia.
B)Archaea.
C)Bacteria.
D)Fungi.
E)Plantae.

Question 31

Which of the following best defines a strain in microbiological terms?

A)a pure culture that is not totally identical to other cultures of the same species
B)a group of organisms with a limited geographical distribution
C)a mixed population of cells,which are genetically distinct,but with highly similar phenotypic characteristics
D)groups of cells all derived from and identical to a single parent species
E)same as a species

Question 32

Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall?

A)Animalia
B)Bacteria
C)Fungi
D)Plantae
E)Protist

Question 33

Into which group would you place a multicellular heterotroph with chitin cell walls?

A)Animalia
B)Archaea
C)Bacteria
D)Fungi
E)Plantae

Question 34

One of the most popular taxonomic tools is DNA fingerprinting to develop profiles of organisms.These profiles provide direct information about

A)enzymatic activities.
B)protein composition.
C)the presence of specific genes.
D)antigenic composition.
E)the similarities between nucleotide sequences.

Question 35

Serological testing is based on the fact that

A)all bacteria have the same antigens.
B)antibodies react specifically with an antigen.
C)the human body makes antibodies against bacteria.
D)antibodies cause the formation of antigens.
E)bacteria clump together when mixed with any antibodies.

Question 36

Which of the following criteria is most useful in determining whether two organisms are related?

A)Both ferment lactose.
B)Both are gram-positive.
C)Both are motile.
D)Both are aerobic.

Question 37

Use the dichotomous key in Table 10.2 to identify a gram-negative coccus.

A)Neisseria
B)Pseudomonas
C)Staphylococcus
D)Streptococcus
E)Micrococcus

Question 38

Table 10.2

Use the dichotomous key in Table 10.2 to identify a gram-negative cell that ferments lactose and uses citric acid as its sole carbon source.

A)Citrobacter
B)Escherichia
C)Lactobacillus
D)Pseudomonas
E)Staphylococcus

Question 39

Nucleic acid hybridization is based on the fact that

A)the strands of DNA can be separated.
B)a chromosome is composed of complementary strands.
C)pairing between complementary bases occurs.
D)DNA is composed of genes.
E)all cells have DNA.

Question 40

Figure 10.3 This figure shows the results of a gel electrophoresis separation of restriction fragments of the DNA of different organisms.

In Figure 10.3,which two are most closely related?

A)1 and 3
B)2 and 4
C)3 and 5
D)2 and 5
E)4 and 5

Question 41

Which one of the following characteristics most reasonably indicates that two microorganisms are closely related?

A)Both are cocci.
B)Both ferment lactose.
C)Their DNA can hybridize together.
D)Both normally live in clams.
E)Both are motile.

Question 42

Serological testing is used for screening bacterial isolates for similarities.

Question 43

At this point in time,scientists believe the vast majority of the domain Bacteria have been discovered.

Question 44

Data collected to date indicate that

A)humans and marine mammals cannot be infected by the same pathogens.
B)marine mammals do not get infectious diseases.
C)new species of bacteria will not be discovered in wild animals.
D)marine mammals don't have an immune system.
E)None of the answers is correct.

Question 45

Figure 10.4
In the cladogram shown in Figure 10.4,which two organisms are most closely related?

A)Streptomyces and Micrococcus
B)Micrococcus and Mycobacterium
C)Mycobacterium and Lactobacillus
D)Streptomyces and Lactobacillus
E)Streptomyces and Mycobacterium

Question 46

Fatty acid methyl ester analysis is commonly used

A)in bacterial identification.
B)in DNA sequencing reactions.
C)in serological identification methods.
D)in DNA fingerprinting.

Question 47

Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?

A)Animalia
B)Fungi
C)Plantae
D)Firmicutes (gram-positive bacteria)
E)Proteobacteria (gram-negative bacteria)

Question 48

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

A)Animalia
B)Fungi
C)Plantae
D)Firmicutes (gram-positive bacteria)
E)Proteobacteria (gram-negative bacteria)

Question 49

When building a cladogram,the length of the horizontal branch is based on the calculated percent similarity between organisms.

Question 50

The cell membranes of all three domains are composed of straight carbon chains attached to
glycerol by ester linkage.

Question 51

As molecular techniques improve,scientists are finding it necessary to reclassify some genera.

Question 52

When performing phage typing to identify an unknown bacterium,you must have ________ in your possession.

A)DNA that will hybridize to the DNA of the bacterium to be identified
B)RNA that will hybridize to the RNA of the bacterium to be identified
C)antiserum containing antibodies that will bind to the bacterium to be identified
D)fluorescent molecules that will light up when bound to the DNA of the bacterium
E)viruses that will specifically infect the bacterium you're trying to identify

Question 53

Chloroplasts possess circular DNA and reproduce by binary fission.

Question 54

The highest level in the current taxonomic hierarchy is "Kingdom."

Question 55

For a serological bacterial identification test to be performed,you must have ________ in your possession.

A)DNA that will hybridize to the DNA of the bacterium to be identified
B)RNA that will hybridize to the RNA of the bacterium to be identified
C)antiserum containing antibodies that will bind to the bacterium to be identified
D)fluorescent molecules that will light up when bound to the DNA of the bacterium
E)viruses that will specifically infect the bacterium you're trying to identify

Question 56

Once a culture is purified,the next logical step in the process of identifying bacteria is biochemical testing.

Question 57

In a direct ELISA test,the method is determining if ________ is/are present in the patient's sample by attempting to bind a labeled antibody to it.

A)antibodies against a pathogen found in a patient's blood
B)an antigen from a particular pathogen
C)a bacteriophage that can infect a particular bacterial strain
D)a known sequence of DNA from a pathogen

Question 58

Pure cultures of the same species are not always identical in all ways.

Question 59

Western blotting is an immunological test used to identify the antibodies in the serum of an individual suspected of having Lyme disease.

Question 60

Flow cytometry,where a cell is passed through a light source such as a laser beam,can directly indicate all EXCEPT which one of the following about a cell?

A)size
B)shape
C)density
D)identity

Question 61

You are studying a type of bacteria isolated from the acidic water runoff of a mining operation.You subject two batches of the same bacteria type to different environmental growth conditions.One batch is grown at pH 2,while the other is grown at pH 7.All other environmental parameters are kept identical between the two batches.You then collect their proteins and run a Western blot using an antibody that binds to a proton efflux pump protein (which actively expends energy to pump protons out of a cell).How would you characterize the information obtained in this experiment? What does it tell you,and why is that potentially valuable information?

Question 62

Figure 10.5

Choose one of the phylogenetic schemes in Figure 10.5 and explain why you feel it is preferable to the others.

Question 63

How are a Southern blot and fluorescent in situ hybridization similar and different from each other? What are the pros and cons of each method for identification of microorganisms?

Question 64

Table 10.3

Use the information given in Table 10.3 to answer the following questions.Which organisms are most closely related? On what did you base your answer? DNA from which organisms will probably hybridize?

Question 65

One of the advantages of some newly developed rapid identification tools is that pure cultures are not needed.Why is a pure culture necessary for biochemical tests such as the Enterotube,but not for DNA probes?