Escherichia coli, a member of the family Enterobacteriaceae, was resistant to the antibiotic vancomycin. Which of the following statements explains this discrepancy?
a. The vancomycin disk has most likely ex-pired.
b. Vancomycin should only be used in viral infections, not bacterial infections.
c. The plate is most likely contaminated with another organism.
d. No discrepancy is present. E. coli is resis-tant to vancomycin.
D
Vancomycin works best on gram-positive organisms. E. coli is a gram-negative bacterium and therefore is resistant to vancomycin; most clinically relevant gram-negative bacteria are resistant to vancomycin.
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Which of the following statements about the differences between prokaryotic and eukaryotic genomes is FALSE?
A. Prokaryotic genomes are less complex than eukaryotic genomes. B. Prokaryotic genomes have centromeres, whereas eukaryotic genomes do not. C. Eukaryotic genomes have telomeres, whereas prokaryotic genomes do not. D. Prokaryotic genomes have one origin of replication, whereas eukaryotic genomes have multiple origins of replication. E. Chromosomes of prokaryotes have little repetitive DNA compared with chromosomes of eukaryotes.
The first case in an epidemic is called the ________.
A. index case B. break case C. prime case D. alpha case
A carpel is the
a. same as a megasporophyll. b. structure producing pollen grains. c. component making up the anther. d. synonym for microsporophyll.
The intermediate host for a blood fluke is a:
a. human. b. cow. c. dog. d. cat.
e. snail.