Exam 24: Early Life and the Diversification of Prokaryotes

Please use the following information to answer the question(s) below. A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from bacteriophages and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. -Adherence to the intestinal lining by this bacterium is due to its possession of

The table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question(s). Table 24.1 -Which species is probably an important contributor of organic compounds such as sugars, which are then passed up through aquatic food chains?

Please use the following information to answer the question(s) below. A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from bacteriophages and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. -The cell also lacks F factors and F plasmids. Which mechanism(s) of genetic recombination can possibly take place? 1) conjugation 2) transduction 3) transformation

Which of the following oxidizes inorganic substances to obtain energy that is used, in part, to fix CO₂?

The following question(s) are based on the observation that several dozen different proteins comprise the prokaryotic flagellum and its attachment to the prokaryotic cell, producing a highly complex structure. -If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of molluscs (such as squids and octopi), then

Please use the following information to answer the question(s) below. In Figure 24.1, data are presented from an eight-year experiment in which 12 populations of Escherichia 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 24.1 -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 means by which beneficial mutations might be transmitted horizontally to other E. coli cells?

Approximately how far back in time does the fossil record extend?

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

Figure 24.2 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 24.2 to answer the following question(s). Figure 24.2 -How is the recipient cell different at time D than it was at time A?

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 of the following terms is (are) applicable to the relationship between the two kinds of bacteria? 1) mutualism 2) parasitism 3) symbiosis 4) metabolic cooperation

The thermoacidophile Sulfolobus acidocaldarius lacks peptidoglycan, but still possesses a cell wall. What is likely to be true of this species? 1) It is a bacterium. 2) It is an archaean. 3) The optimal pH of its enzymes lies above pH 7. 4) The optimal pH of its enzymes lies below pH 7. 5) It could inhabit certain hydrothermal springs. 6) It could inhabit alkaline hot springs.

The table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question(s). Table 24.1 -Which two species should have much more phospholipid, in the form of bilayers, in their cytoplasm than most other bacteria?

Although not present in all bacteria, this cell covering often enables cells that possess it to resist the defenses of host organisms, especially their phagocytic cells.

Mitochondria are thought to be the descendants of certain alpha proteobacteria. They are, however, no longer able to lead independent lives because most genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?

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

In 2009, which of the following did scientists discover was possible on early Earth?

Match the numbered terms to the description that follows. Choose all appropriate terms. 1) autotroph 2) heterotroph 3) phototroph 4) chemotroph An organism that obtains both carbon and energy by ingesting prey

Which statement about the genomes of prokaryotes is correct?

The table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question(s). Table 24.1 -Species D is pathogenic if it gains access to the human intestine. Which other species, if it coinhabited a human intestine along with species D, is most likely to result in a recombinant species that is both pathogenic and resistant to some antibiotics?

The first genetic material on early Earth was most likely