Exam 27: Bacteria and Archaea

Hershey and Chase performed an elegant experiment that convinced most biologists that DNA, rather than protein, was the genetic material. This experiment subjected bacteria to the same gene transfer mechanism as occurs in

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following questions. -Which species is most self-sustaining in terms of obtaining nutrition in environments containing little fixed nitrogen or carbon?

The following questions refer to Figure 27.1. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population. Figure 27.1 -If the experimental population of E. coli lacks an F factor or F plasmid, and if bacteriophages are excluded from the bacterial cultures, then which of these is (are)means by which beneficial mutations might be transmitted horizontally to other E. coli cells?

Prokaryotic ribosomes differ from those present in eukaryotic cytosol. Because of this, which of the following is correct?

Which of the following statements is not true?

Which statement about the genomes of prokaryotes is correct?

Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature, which statement concerning mycoplasmas should be true?

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following questions. -Which two species should have much more phospholipid, in the form of bilayers, in their cytoplasms than most other bacteria?

Which of the following involves metabolic cooperation among prokaryotic cells?

Genetic variation in bacterial populations cannot result from

The termite gut protist, Mixotricha paradoxa, has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which term(s)is (are)applicable to the relationship between the two kinds of bacteria? 1)mutualism 2)parasitism 3)symbiosis 4)metabolic cooperation

If a bacterium regenerates from an endospore that did not possess any of the plasmids that were contained in its original parent cell, the regenerated bacterium will probably also

The following questions refer to Figure 27.1. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population. Figure 27.1 -E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions of this experiment, what should be true of E. coli's generation time (especially early in the course of the experiment, but less so later on)?

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 fish that has been salt-cured subsequently develops a reddish color. You suspect that the fish has been contaminated by the extreme halophile, Halobacterium. Which of these features of cells removed from the surface of the fish, if confirmed, would support your suspicion? 1)the presence of the same photosynthetic pigments found in cyanobacteria 2)cell walls that lack peptidoglycan 3)cells that are isotonic to conditions on the surface of the fish 4)cells containing bacteriorhodopsin 5)the presence of very large numbers of ion pumps in its plasma membrane

Match the numbered terms to the description that follows. Choose all appropriate terms. 1)autotroph 2)heterotroph 3)phototroph 4)chemotroph A prokaryote that obtains both energy and carbon as it decomposes dead organisms

Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces? 1)capsules 2)endospores 3)fimbriae 4)plasmids 5)flagella

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following questions. Figure 27.2 -How is the recipient cell different at Time D than it was at Time A?