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Chapter 3. Classification of Bacteria

Eubacteria that lack cell walls and do not synthesize the precursors of peptidoglycan are called

(A) Gram-negative bacteria

(B) Viruses

(C) Mycoplasmas

(D) Serovar

(E) Bacilli

Archaebacteria can be distinguished from eubacteria by their lack of



(C) Ribosomes

(D) Peptidoglycan

(E) Nucleus

A 16-year-old cystic fibrosis patient is admitted to the hospital. A sputum culture yields Burkholderia cepacia. Subsequently, there are two other patients with B. cepacia bacteremia, and the organism is cultured from the sputum of four additional patients. During this nosocomial outbreak of B. cepacia, 50 environmental and 7 patient isolates are being subtyped to identify the source of the outbreak. Which of the following techniques would be most useful in this endeavor?

(A) Culture

(B) Ribotyping

(C) 16S rRNA sequencing

(D) Antimicrobial susceptibility testing

(E) Nucleic acid sequencing

An unculturable Gram-positive microorganism has been visualized in tissue specimens obtained from patients with a previously undescribed disease. Which of the following techniques would be most useful in identifying this organism?

(A) Serology

(B) PCR amplification and sequencing of rRNA genes

(C) Multilocus VNTR analysis

(D) SDS-polyacrylamide gel electrophoresis


The DNA polymerase from T. aquaticus is an important component of DNA amplification methods such as the PCR. This organism can grow at temperatures above 100°C. Organisms that are capable of growth at these temperatures are referred to as

(A) Mesophiles

(B) Psychrophiles

(C) Halophiles

(D) Thermophiles

(E) Chemolithotrophs

A bacterium with a genome having a G + C content of 45% harbors a plasmid encoding a gene with a G + C content of 55%. Which one of the following conclusions could be drawn?


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