Ch19 Exam Questions Microbial Taxonomy And The Evolution Of

Prescott's Microbiology, 11e (Willey)

Chapter 19 Microbial Taxonomy and the Evolution of Diversity

1) Microorganisms do not generally reproduce sexually; therefore, species are usually defined by phenotypic and genotypic similarities.

2) In an approach called ________ taxonomy, relatedness is determined by a wide range of phenotypic and genotypic information.

3) Serovars are strains of a species that have distinctive antigenic properties.

4) Microbial species are collections of strains that share many stable properties in common but differ significantly from other strains.

5) The type strain is a well-characterized strain to which other strains are compared for inclusion in or exclusion from a particular species.

6) The type strain is the most representative strain of a particular species.

7) Bacterial strains that are characterized by biochemical differences are called ________.

8) Bacterial strains that have distinct antigenic properties are called ________.

9) rRNA signature sequences can be used to place microorganisms in the correct domain.

10) The G + C content of a DNA sample can be estimated from its melting temperature.

11) Conjugation is useful for determining relatedness between bacteria at the species level because it never occurs between organisms of different genera.

12) Phylogenetic trees show inferred evolutionary relationships in the form of multiple branching lineages connected by nodes.  

13) Transformation is not useful in determining relatedness between two organisms because it frequently crosses genera.

14) The ________ hypothesis proposes that mitochondria and chloroplasts developed from free-living prokaryotes that invaded a precursor to the eukaryotes and established a stable relationship.

15) Chromosomal gene exchange is not useful in classification studies because prokaryotes do not reproduce sexually.

16) Extensive horizontal gene transfer between domains greatly simplifies the construction of phylogenetic trees.

17) The pace of evolution does not always occur at a constant rate but is periodically interrupted by rapid bursts of speciation; this is known as ________ ________.

18) Although there are other classification schemes for prokaryotes, the one used in Bergey's Manual is currently considered by most microbiologists to be the most accurate.

19) The second edition of Bergey's Manual groups pathogenic species together rather than in phylogenetic groups.

20) The scientific study of organisms with the ultimate goal of characterizing and arranging them in an orderly manner is ________.

A) taxonomy

B) classification

C) systematics

D) identification

21) The assignment of names to taxonomic groups is referred to as ________.

A) taxonomy

B) nomenclature

C) systematics

D) identification

22) The determination of the taxon to which an organism belongs is called ________.

A) taxonomy

B) classification

C) systematics

D) identification

23) The science dealing with classification is called ________.

A) taxonomy

B) nomenclature

C) systematics

D) identification

24) The arrangement of organisms into groups is best described as ________.

A) taxonomy

B) classification

C) systematics

D) identification

25) A classification system based on mutual similarity that involves comparing as many characteristics as possible is called a ________ system.

A) phylogenetic

B) phyletic

C) phenetic

D) determinative systematic

26) A classification system based on evolutionary relationships is called a ________ system.

A) phylogenetic

B) phenetic

C) systematic

D) determinative

27) Which of the following is useful in biological systematics?

A) Physiology

B) Epidemiology

C) Ecology

D) All of the choices are correct.

28) A general term used to describe groups based on mutual similarity or evolutionary relatedness is ________.

A) class

B) taxa

C) system

D) group

29) A population descending from a single organism or pure culture isolate is called a ________.

A) genus

B) species

C) subspecies

D) strain

30) Which of the following is an example of the use of the binomial system devised by Linnaeus?

A) Escherichia coli

B) Enterobacteriaceae

C) Enterobacteriales

D) O157:H7

31) The organisms in which of the following are more closely related?

A) Order

B) Family

C) Class

D) Phylum

32) The binomial system of nomenclature assigns each organism a scientific name consisting of ________.

A) species and strain

B) kingdom and species

C) genus and species

D) kingdom and genus

33) The general order of classification below the domain or kingdom level is ________.

A) phyla, order, class, family, genus, species

B) phyla, order, family, class, genus, species

C) phyla, class, family, order, genus, species

D) phyla, class, order, family, genus, species

34) Mole percent (G+C) of DNA is useful for determining relatedness at the ________ level.

A) kingdom

B) class

C) genus

D) None of the choices are correct.

35) Stable annealing due to hydrogen bonding between DNAs of similar nucleotide sequence from different organisms is referred to as ________.

A) hydrolysis

B) restriction

C) hybridization

D) ligation

36) The temperature at which one DNA molecule separates from the other DNA molecule in a double strand is called the ________ temperature.

A) separation

B) melting

C) destabilizing

D) mobilization

37) Which of the following is not true about the G + C content percentages in DNA of organisms?

A) Organisms with similar G + C percentages have similar base sequences.

B) Organisms with different G + C percentages have dissimilar base sequences.

C) Similar G + C percentages only suggests relatedness if the two organisms are also alike phenotypically.

D) All of the choices are correct.

38) Conserved indels are ________.

A) a type of transposable sequence characteristic of a particular genus, and useful for taxonomic analysis

B) sequences in eukaryotic mRNAs that are removed by RNA splicing

C) a type of signature sequence particularly useful for phylogenetic analysis

D) sequences of protein coding genes that are found altered in related species due to their tendency to accumulate small deletions

39) The analysis of genetic relatedness by observing the DNA fragmentation patterns resulting from restriction endonuclease cleavage is referred to as ________.

A) genetic fingerprinting

B) genetic patterning

C) genetic restriction

D) genetic chunking

40) An unrooted tree containing four unrelated species can become rooted by adding ________.

A) a descendant group related to two of the species

B) an unrelated outgroup

C) a distantly related outgroup

D) a descendant related to only one of the species

41) Small, random genetic changes that occur over generations is known as ________.

A) microgenesis

B) progenesis

C) degenesis

D) anagenesis

42) According to genome analysis, a member of the genus ________ is most closely related to the mitochondrion.

A) Escherichia

B) Agrobacterium

C) Prochloron

D) Rickettsia

43) According to the endosymbiosis hypothesis ________.

A) the first endosymbiotic event involved an anaerobic bacterium

B) the first endosymbiont was a fermentative organism

C) the mitochondrion evolved from the same endosymbiont as the hydrogenosome

D) All of the choices are correct.

44) The ancestors of modern ________ performed the oxygenic photosynthesis responsible for converting our anoxic planet to an oxygenated one.

A) Crenarchaeota

B) Proteobacteria

C) Firmicutes

D) Cyanobacteria

45) A theoretical concept that is used to understand how and why certain organisms can be sorted into discrete taxonomic groups is known as the ________.

A) endosymbiotic theory

B) species concept

C) phylogenetic concept

D) genotypic concept

46) Which of the following is true about Bergey's Manual?

A) The first edition is mostly phenetic while the second edition is more phylogenetic.

B) The first edition is largely phylogenetic while the second edition is more phenetic.

C) The first and second editions are both largely phenetic.

D) The first and second editions are both largely phylogenetic.

47) The second edition of Bergey's Manual classifies bacteria ________.

A) phylogenetically

B) phonetically

C) numerically

D) None of the choices are correct.

There are many molecular techniques to identify taxonomy of microorganisms. Match each technique to its proper resolution.

A) Genus, species, and subspecies

B) Family and genus

C) Species, subspecies, and strain

D) Family, genus, species, subspecies, and strain

48) Genome sequencing

49) 16S rDNA sequencing

50) Mole % G+C

51) Genomic fingerprinting

52) Fatty acid methyl ester (FAME) analysis is particularly important in public health because in this application, microbiologists seek to identify specific microbial pathogens in _________.

A) food and water

B) patient samples

C) genomic analysis

D) genetic diseases

53) Many clinical microbiology laboratories and public health laboratories use techniques such as microbial staining, microbial growth, enzymatic testing, fermentation testing, and microscopic analysis to identify pathogens in samples. Which categories of classical characteristics for taxonomy are represented here? (Check all that apply.)

A) Morphological characteristics

B) Physiological and metabolic characteristics

C) Biochemical characteristics

D) Molecular characteristics

54) On a phylogenetic tree, each node (branchpoint) represents a divergence event, and the length of the branches represents the number of molecular changes that have taken place between the nodes.

55) Place the five steps in building a phylogenetic tree in the proper order, from first construction step to last.

1. The nucleotide or amino acid sequence must be aligned.

2. The alignment must be examined for a phylogenetic signal.

3. Choose which tree-building method to use (common ones are phenetic or cladistic).

4. Application of a selected method, using computer analysis.

5. Manual examination of the tree.

56) One hypothesis explaining the first nucleated eukaryotic cell is based upon the fusion of an archaeon and a bacterium that, over time, saw archaeal genes involved in metabolism being lost while bacterial genes involved in information processing were also degraded.

57) A theory of eukaryotic cells and nuclear origin is based on endosymbioses, where an archaeal cell is thought to have engulfed a bacterium, which then donated genes that would eventually become the nuclear genome of an ancestral eukaryote.

58) Genomic DNA sequences seem to support the idea that the first eukaryotic cell arose from within the ________ lineage.

A) archaeal

B) bacterial

C) viral

D) last universal common ancestor (LUCA)

59) Which of the following has not been considered as a "gold standard" taxonomic method applied to species designation.

A) DNA-DNA hybridization (DDH)

B) Melting temperature of the DNA (a reflection of the G+C content)

C) Average nucleotide identity

D) Microscopic cell phenotype

60) Phylogenetic trees are usually constructed using either a distance-based ________ approach, or a characteristic ________ approach. 

61) The two major approaches used in taxonomic classification of microorganisms that have been isolated and grown in pure culture are termed ________ and ________.

62) A(n) ________ tree simply represents phylogenetic relationships but does not indicate which organisms are more primitive relative to others.  In contrast, a(n) ________ tree gives a node that serves as the common ancestor and shows the development of the species from this origin.

63) In an effort to clarify and standardize microbial taxonomy, the International Committee on Systematics of Prokaryotes (ICSP) recommends four criteria to meet a "gold standard" for species assignment. Which of the following is not part of the criteria?

A) Bioinformatics ecotype analysis showing similar environmental niches

B) Phenotypic similarity to others microorganisms in the group

C) Whole genome similarity (as determined by DDH) of at least 70%

D) Melting temperature of the DNA (reflection of the G+C content) within 58°C

E) Less than 3% divergence in rRNA gene sequence

64) Select the characteristics that are used in the morphological identification of microorganisms.

A) Cell shape

B) Staining behavior

C) Salt tolerance

D) Presence of cilia and flagella

E) Fermentation products

F) Temperature growth range

65) The rationale behind the construction of phylogenetic trees is based on ________.

A) the evolutionary relationship between organisms determined by aligning nucleotide sequences and identifying divergence events

B) differences in morphological and physiological characteristics between organisms

C) comparisons between microorganisms that occupy different ecological niches

D) comparisons made between organisms based on their protein composition identified by MALDI-ToF mass spectrometry

66) New ecotypes arise largely as a result of ________.

A) random mutations that confer a growth advantage and are passed to subsequent generations

B) horizontal gene transfer between species

C) viral infection and incorporation of viral genes into the host genome

D) endosymbiosis whereby smaller organisms either combine or are engulfed by a larger, eukaryotic organism