27.6 Prokaryotes have both beneficial and harmful impacts on humans Flashcards
69) Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods would not generally inhibit bacterial growth?
A) Refrigeration: Slows bacterial metabolism and growth.
B) Closing previously opened containers: Prevents more bacteria from entering, and excludes O2.
C) Pickling: Creates a pH at which most bacterial enzymes cannot function.
D) Canning in heavy sugar syrup: Creates osmotic conditions that remove water from most bacterial cells.
E) Irradiation: Kills bacteria by mutating their DNA to such an extent that their DNA-repair enzymes are overwhelmed.
B) Closing previously opened containers: Prevents more bacteria from entering, and excludes O2.
70) Many physicians administer antibiotics to patients at the first sign of any disease
symptoms. Why can this practice cause more problems for these patients, and for others not
yet infected?
A) The antibiotic administered may kill viruses that had been keeping the bacteria in check.
B) Antibiotics may cause other side effects in patients.
C) Overuse of antibiotics can select for antibiotic-resistant strains of bacteria.
D) Particular patients may be allergic to the antibiotic.
E) Antibiotics may interfere with the ability to identify the bacteria present.
C) Overuse of antibiotics can select for antibiotic-resistant strains of bacteria.
71) Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently,
assuming that nothing is done to counter the reduction of intestinal bacteria, a hospital
patient who is receiving broad-spectrum antibiotics is most likely to become
A) unable to fix carbon dioxide.
B) antibiotic resistant.
C) unable to fix nitrogen.
D) unable to synthesize peptidoglycan.
E) deficient in certain vitamins.
E) deficient in certain vitamins.
72) Which statement about gram-negative bacteria is correct?
A) Penicillins are the best antibiotics to use against them.
B) They often possess an outer membrane containing toxic lipopolysaccharides.
C) Their chromosomes are composed of DNA tightly wrapped around large amounts of histone proteins.
D) Their cell walls are primarily composed of peptidoglycan.
B) They often possess an outer membrane containing toxic lipopolysaccharides.
1) Genetic variation in bacterial populations cannot result from
A) transduction.
B) transformation.
C) conjugation.
D) mutation.
E) meiosis.
E) meiosis.
2) Photoautotrophs use
A) light as an energy source and CO2 as a carbon source.
B) light as an energy source and methane as a carbon source.
C) N2 as an energy source and CO2 as a carbon source.
D) CO2 as both an energy source and a carbon source.
E) H2S as an energy source and CO2 as a carbon source.
A) light as an energy source and CO2 as a carbon source.
3) Which of the following statements is not true?
A) Archaea and bacteria have different membrane lipids.
B) Both archaea and bacteria generally lack membrane-enclosed organelles.
C) The cell walls of archaea lack peptidoglycan.
D) Only bacteria have histones associated with DNA.
E) Only some archaea use CO2 to oxidize H2, releasing methane.
D) Only bacteria have histones associated with DNA.
4) Which of the following features of prokaryotic biology involves metabolic cooperation
among cells?
A) binary fission
B) endospore formation
C) endotoxin release
D) biofilms
E) photoautotrophy
D) biofilms
5) Which prokaryotic group is mismatched with its members?
A) Proteobacteriadiverse gram-negative bacteria
B) Gram-positive bacteriasymbionts in legume root nodules
C) Spirocheteshelical heterotrophs
D) Chlamydiasintracellular parasites
E) Cyanobacteriasolitary and colonial photoautotrophs
B) Gram-positive bacteriasymbionts in legume root nodules
6) Plant-like photosynthesis that releases O2 occurs in
A) cyanobacteria.
B) chlamydias.
C) archaea.
D) actinomycetes.
E) chemoautotrophic bacteria.
A) cyanobacteria.
