Question 1

Define the term "metagenomics" and explain why growth in this field has led to an increase in SSU rRNA species designations.

Accepted Answer

Metagenomics is the practice of sequenci

Question 2

During the Long-Term Evolution Experiment (LTEE), investigators found a Cit⁺ strain of Escherichia coli that allowed fast growth on citrate buffer after 33,000 generations. The ability to catabolize citrate evolved at this time through

Accepted Answer

A)  acquiring the ability to exploit new ecological niches. 
B)  becoming pathogens. 
C)  becoming dependant on a symbiotic partner's resources. 
D)  becoming pathogens and becoming dependent on a symbiotic partner's resources. 
E)  losing the ability to exploit new ecological niches. 
A)  acquiring the ability to exploit new ecological niches. 
B)  becoming pathogens. 
C)  becoming dependant on a symbiotic partner's resources. 
D)  becoming pathogens and becoming dependent on a symbiotic partner's resources. 
E)  losing the ability to exploit new ecological niches.

Question 3

The loss of genes encoding for unselected traits is known as

Accepted Answer

A)  random mutation. 
B)  natural selection. 
C)  reductive evolution. 
D)  clade evolution. 
E)  random recombination. 
A)  random mutation. 
B)  natural selection. 
C)  reductive evolution. 
D)  clade evolution. 
E)  random recombination.

Question 4

A dichotomous key is a

Accepted Answer

A)  battery of biochemical tests used to identify organisms in a particular taxon. 
B)  detailed description of a taxon with diagnostic purposes. 
C)  registered valid name for a specific taxon. 
D)  comprehensive list of characteristics that define a taxonomic category. 
E)  series of yes/no choices that successively narrows down a possible taxonomic category. 
A)  battery of biochemical tests used to identify organisms in a particular taxon. 
B)  detailed description of a taxon with diagnostic purposes. 
C)  registered valid name for a specific taxon. 
D)  comprehensive list of characteristics that define a taxonomic category. 
E)  series of yes/no choices that successively narrows down a possible taxonomic category.

Question 5

Human diseases caused by defective mitochondrial DNA include all of the following EXCEPT

Accepted Answer

A)  sickle cell anemia. 
B)  forms of ataxia. 
C)  dystonia. 
D)  Parkinson's disease. 
E)  chorea. 
A)  sickle cell anemia. 
B)  forms of ataxia. 
C)  dystonia. 
D)  Parkinson's disease. 
E)  chorea.

Question 6

The figure below depicts a metabolist model for CO₂ fixation as the basis for biosynthesis as proposed by Morowitz and Wächterhäuser. Discuss the pathway and determine what its outcome is.

Accepted Answer

Polymerization of CO₂ and H₂ could have

Question 7

Which of the following is NOT correct regarding conditions for life on Earth?

Accepted Answer

A)  Generation of life requires continual input of energy. 
B)  The main source of energy for life is nuclear fusion reactions within the sun. 
C)  It depends on a temperature range permitting liquid water. 
D)  Life requires elements that lead to the formation of organic molecules. 
E)  Life requires a CO₂-rich atmosphere. 
A)  Generation of life requires continual input of energy. 
B)  The main source of energy for life is nuclear fusion reactions within the sun. 
C)  It depends on a temperature range permitting liquid water. 
D)  Life requires elements that lead to the formation of organic molecules. 
E)  Life requires a CO₂-rich atmosphere.

Question 8

Taxonomy can be defined as the

Accepted Answer

A)  classifying of life forms into different categories with shared traits. 
B)  recognition of the class of a given microbe isolated in pure culture. 
C)  identification of a species in a sample or collection. 
D)  recognition of different classes of life. 
E)  testing of metabolic reactions to predict pathogenicity. 
A)  classifying of life forms into different categories with shared traits. 
B)  recognition of the class of a given microbe isolated in pure culture. 
C)  identification of a species in a sample or collection. 
D)  recognition of different classes of life. 
E)  testing of metabolic reactions to predict pathogenicity.

Question 9

The following is correct about a probabilistic indicator for bacterial identification, EXCEPT that

Accepted Answer

A)  it requires a predefined database of known bacteria. 
B)  numerous strains of each species in well-studied habitats must be isolated in pure culture and tested for a defined number of traits. 
C)  it is based on yes/no choices that successively narrow down the identification of a taxon. 
D)  it only works if the bacterial isolate coincides with a member of a predefined database. 
E)  fractions of positive results for certain traits are noted as the probability of obtaining a positive result. 
A)  it requires a predefined database of known bacteria. 
B)  numerous strains of each species in well-studied habitats must be isolated in pure culture and tested for a defined number of traits. 
C)  it is based on yes/no choices that successively narrow down the identification of a taxon. 
D)  it only works if the bacterial isolate coincides with a member of a predefined database. 
E)  fractions of positive results for certain traits are noted as the probability of obtaining a positive result.

Question 10

The word "symbiosis" is usually understood to mean ________, a relationship in which both partners benefit and may absolutely require each other.

Accepted Answer

A)  comensalism 
B)  parasitism 
C)  mutualism 
D)  predation 
E)  competition 
A)  comensalism 
B)  parasitism 
C)  mutualism 
D)  predation 
E)  competition

Question 11

Refer to the figure below and briefly discuss the possible origin of the genetic code.

Accepted Answer

An early pretranslation mechanism of ami

Question 12

The Long-Term Evolution Experiment (LTEE) has been conducted by Richard Lenski at Michigan State University since 1988. The purpose of the experiment is to observe evolution in action in a laboratory environment. Use the figure below to explain what physiological adaptations allowed one of the Escherichia coli strains to grow to a much higher density after 33,000 generations.

Accepted Answer

Originally, twelve populations of Escher

Question 13

Appearance of a new trait in experimental evolution consists of which three basic stages?

Accepted Answer

A)  fixing, staining, and decolorizing 
B)  disabling gene expression, regulation, slow cell growth 
C)  potentiation, actualization, and refinement 
D)  gene amplification, purification, and subcloning 
E)  restriction digestion, agarose gel electrophoresis, and staining 
A)  fixing, staining, and decolorizing 
B)  disabling gene expression, regulation, slow cell growth 
C)  potentiation, actualization, and refinement 
D)  gene amplification, purification, and subcloning 
E)  restriction digestion, agarose gel electrophoresis, and staining

Question 14

Cyanobacterial endosymbionts in the protist ________retain cell walls and some metabolism, thus serving as a model for cyanobacterial uptake.

Accepted Answer

A)  Paramecium bursaria 
B)  Paramecium aurelia 
C)  Cyanophora paradoxa 
D)  Glaucocystophyta sp. 
E)  Entamoeba hystolitica 
A)  Paramecium bursaria 
B)  Paramecium aurelia 
C)  Cyanophora paradoxa 
D)  Glaucocystophyta sp. 
E)  Entamoeba hystolitica

Question 15

The sum total of all life on Earth is called the

Accepted Answer

A)  lithosphere. 
B)  mantle. 
C)  core. 
D)  atmosphere. 
E)  biosphere. 
A)  lithosphere. 
B)  mantle. 
C)  core. 
D)  atmosphere. 
E)  biosphere.

Question 16

Spikes in ________ content often indicate that a horizontal gene transfer has occurred in the genome.

Accepted Answer

A)  GC 
B)  AC 
C)  GT 
D)  AT 
E)  CU 
A)  GC 
B)  AC 
C)  GT 
D)  AT 
E)  CU

Question 17

Which of the following is the organizing body that sets the rules for naming a new prokaryotic species or taxa?

Accepted Answer

A)  Bergey's Manual of Determinative Bacteriology 
B)  the International Committee on Systematics of Prokaryotes 
C)  the International Journal of Systematic and Evolutionary Microbiology 
D)  the American Society for Microbiology 
E)  the World Health Organization 
A)  Bergey's Manual of Determinative Bacteriology 
B)  the International Committee on Systematics of Prokaryotes 
C)  the International Journal of Systematic and Evolutionary Microbiology 
D)  the American Society for Microbiology 
E)  the World Health Organization

Question 18

Which label on the figure below is NOT correct?

Accepted Answer

A)  A-oldest stromatolites 
B)  B-chloroplasts and mitochondria 
C)  C-colonial organism 
D)  D-filamentous cyanobacteria 
E)  E-early eukaryotes 
A)  A-oldest stromatolites 
B)  B-chloroplasts and mitochondria 
C)  C-colonial organism 
D)  D-filamentous cyanobacteria 
E)  E-early eukaryotes

Question 19

The ancestral organism that gave rise to the modern-day chloroplast was

Accepted Answer

A)  rickettsia. 
B)  a cyanobacterium. 
C)  Wolbachia. 
D)  a rhizobial bacteroid. 
E)  a methanogen. 
A)  rickettsia. 
B)  a cyanobacterium. 
C)  Wolbachia. 
D)  a rhizobial bacteroid. 
E)  a methanogen.

Question 20

Explain how studying the evolutionary rate of RNA viruses in comparison to DNA viruses can help explain the evolutionary rate in early Earth.

Accepted Answer

RNA viruses (such as HIV or influenza) m

Exam 17: Origins and Evolution

Define the term "metagenomics" and explain why growth in this field has led to an increase in SSU rRNA species designations.

During the Long-Term Evolution Experiment (LTEE), investigators found a Cit⁺ strain of Escherichia coli that allowed fast growth on citrate buffer after 33,000 generations. The ability to catabolize citrate evolved at this time through

The loss of genes encoding for unselected traits is known as

A dichotomous key is a

Human diseases caused by defective mitochondrial DNA include all of the following EXCEPT

The figure below depicts a metabolist model for CO₂ fixation as the basis for biosynthesis as proposed by Morowitz and Wächterhäuser. Discuss the pathway and determine what its outcome is.

Which of the following is NOT correct regarding conditions for life on Earth?

Taxonomy can be defined as the

The following is correct about a probabilistic indicator for bacterial identification, EXCEPT that

The word "symbiosis" is usually understood to mean ________, a relationship in which both partners benefit and may absolutely require each other.

Refer to the figure below and briefly discuss the possible origin of the genetic code.

Appearance of a new trait in experimental evolution consists of which three basic stages?

Cyanobacterial endosymbionts in the protist ________retain cell walls and some metabolism, thus serving as a model for cyanobacterial uptake.

The sum total of all life on Earth is called the

Spikes in ________ content often indicate that a horizontal gene transfer has occurred in the genome.

Which of the following is the organizing body that sets the rules for naming a new prokaryotic species or taxa?

Which label on the figure below is NOT correct?

The ancestral organism that gave rise to the modern-day chloroplast was

Explain how studying the evolutionary rate of RNA viruses in comparison to DNA viruses can help explain the evolutionary rate in early Earth.

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

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