Chapter 27: Bacteria And Archaea

Why is salt a good preservative to use for foods such as pork and fish? - Prokaryotes living in the food products will take in excess water and explode. - Salt is a toxin to prokaryotic cells and leads to their death. - Salt breaks down the peptidoglycan found in the capsule of prokaryotes. - Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce. - Salt breaks down the chitin contained in the cell walls of prokaryotes.

Which of the following is not one of the most common prokaryotic cell shapes? Rod-shaped Spiral Cuboidal All of the listed cell shapes are very common. Spherical

Which of the following is a structure that bacteria, archaea, and eukaryotes have? Circular chromosome Nuclear envelope Peptidoglycan cell wall Membrane-enclosed organelles Plasma membrane

Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is __________. - convergent evolution - horizontal gene transfer - identical mutations occurring independently in these distantly related lineages - genetic variation arising from meiosis - genetic variation arising from binary fission

In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the following organisms would be most likely to survive? Photoheterotrophs Thermoacidophilic bacteria Photoautotrophs Chemoheterotrophic bacteria Cyanobacteria

Prokaryotes found inhabiting the Great Salt Lake would be __________. extreme thermophiles methanogens extreme halophiles extremophiles cyanobacteria

What is the function of a bacterial endospore? - To adhere to a substrate or other bacteria - To fix nitrogen - To facilitate persistence in temporarily harsh environments - To transfer DNA from one cell to another - To store the genetic material of the cell

Which of the following is a disease caused by bacteria? Tuberculosis Aids Measles Common cold Smallpox

Which of the following characteristics is a reason why a Gram-stain to distinguish gram-positive from gram-negative bacteria is an important tool in a medical diagnosis of a bacterial infection? - All of the listed characteristics are reasons why a Gram-stain is important in medicine. - The outer membrane of a gram-negative bacterium helps protect it from the body's defenses. - Certain gram-positive bacteria are resistant to antibiotics. - The cell walls of many gram-negative bacteria are toxic. - None of the listed characteristics is a reason why a Gram-stain is important in medicine.

Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria. - Carbon dioxide, nitrogen, water, light, and some minerals - Carbon dioxide, ammonium, water, light, and some minerals - Oxygen, sulfur, light, water, and some minerals - Carbon dioxide, sulfur, light, water, and some minerals - Carbon, nitrogen, light, water, and some minerals

Bacteria that __________ tend to have abundant internal membranes. are gram-negative are photosynthetic All of the listed responses are correct. are pathogenic have flagella

Bacteria function primarily in which ecological role? Parasitism Commensalism Decomposition Mutualism Bacteria are common in all of the listed ecological roles.

The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio. We would call Desulfovibrio a(n) __________. - facultatively anaerobic chemoautotroph - obligately anaerobic chemoautotroph - obligately anaerobic chemoheterotroph - facultatively aerobic chemoheterotroph - There is insufficient information to answer this question.

Which of the following mechanisms is/are (a) means of genetic recombination in prokaryotes? - Transduction - All of the listed mechanisms are means of genetic recombination. - None of the listed mechanisms is a means of genetic recombination. - Transformation - Conjugation

Some prokaryotes stick to their substrate or to one another by means of hairlike appendages, each called a __________. pilus nucleoid capsule heterocyst fimbria

Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls? Gram-negative bacteria Epsilon proteobacteria Spirochetes Cyanobacteria Chlamydias

Antibiotics administered in human medicine work against bacterial infections by __________. - raising the host's body temperature to make a less favorable environment for bacteria - providing resources to lure bacteria away from human cells - stimulating the host's immune system to mount defenses against the bacteria - preventing any cells from dividing - interfering with an aspect of bacterial metabolism or structure that differs from that of eukaryotic cells

An F+ bacterial cell __________. uses fimbriae to transfer DNA transfers DNA by way of transduction acts as a receptor during conjugation acts as a donor during conjugation has many antibiotic resistance genes

What are biofilms? - Biofilms are an antibacterial treatment. - A biofilm is a location where nitrogen has been made available in the environment by bacterial decomposition. - Biofilms are any resource upon which bacterial colonies can grow. - Biofilms are cooperative colonies of bacteria. - A biofilm is the sticky layer surrounding a bacterial cell wall.

Plasmids __________. - replicate independently of the main chromosome - often contain antibiotic resistance genes - allow bacteria to survive adverse conditions - All of the listed responses are correct. - are transferred from one bacterium to another by conjugation

What is the structural feature of gram-positive bacteria that results in their retaining a crystal violet dye stain and thereby being distinguished from gram-negative bacteria in a Gram-stain technique? - Gram-positive bacteria have structurally more complex cell walls. - Gram-positive bacteria lack cell walls. - Gram-positive bacteria have thicker cell walls. - Gram-positive bacteria have additional outer membranes. - Gram-positive bacteria lack peptidoglycan in their cell walls.

Bacteria that use light for their energy source and CO2 for their carbon source are called __________. photoautotrophs chemoautotrophs photoheterotrophs photochemoheterotrophs chemoheterotrophs

Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures? - Early bacterial species needed to be able to locomote and thus developed complex flagella to facilitate this motility - Exaptation - They evolved from earlier, simpler organisms - Flagella evolved as extensions of other bacterial appendages such as pili and fimbriae - Endosymbiosis

Acquiring an R plasmid would allow a bacterium to do what? Conjugate Reduce its metabolic rate Reproduce Resist high temperatures Resist antibiotics

Which of the following is not a true statement concerning bacterial flagella? - Bacterial flagella are homologous to the flagella of eukaryotic cells. - Bacterial flagella originate in and extend from the cell wall and plasma membrane. - There can be more than one flagellum on each bacterial cell. - Bacterial flagella enable bacteria to move. - Bacterial flagella are not covered by the plasma membrane as eukaryotic cells are.

Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships? Delta Gamma Epsilon Alpha Beta

Which of the following does not contribute to bacteria's ability to evolve rapidly? Genetic recombination Mutation Short generation times Sexual reproduction Large populations

What is a difference between the cell walls of prokaryotes and the cell walls of eukaryotes? - There are no cell walls in eukaryotes. - The cell walls of prokaryotes do not resist osmotic pressure. - The cell walls of prokaryotes are made of molecules different from those comprising the cell walls of eukaryotes. - The cell walls of prokaryotes do not play a role in structural support. - Differences in prokaryotic cell wall composition are difficult to discern in the laboratory.

Which of the following statements about cyanobacteria is true? - All of the listed responses are correct. - It can be said that nitrogen-fixing cyanobacteria are the most self-sufficient of all organisms. - Some are single cells, whereas others live in filamentous colonies. - They are the only prokaryotes that perform plantlike, oxygenic photosynthesis. - Some species may carry on nitrogen fixation.

Which subgroup of proteobacteria contains many species that are predators of other bacteria? Gamma Alpha Delta Beta Epsilon