Exam 27: Bacteria and Archaea

Penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, so which prokaryotes should be most vulnerable to inhibition by penicillin?

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 (i.e., 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?

Which of the following features of prokaryotic biology involves metabolic cooperation among cells?

The following questions refer to Figure 27.1 below, which is the same as Figure 27.10 in the textbook. In this 8-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)?

If archaeans are more closely related to eukaryotes than to bacteria, then which of the following is a reasonable prediction?

The following questions refer to structures found in a gram-positive prokaryotic cell. -Not present in all bacteria, this structure enables those that possess it to germinate after exposure to harsh conditions, such as boiling:

The following questions refer to Figure 27.1 below, which is the same as Figure 27.10 in the textbook. In this 8-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 -Which of these can be inferred from Figure 27.1?

Genetic variation in bacterial populations cannot result from

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

Consider the thermoacidophile, Sulfolobus acidocaldarius. Which graph most accurately depicts the expected temperature and pH profiles of its enzymes? (NOTE: the horizontal axes of these graphs are double, with pH above, and temperature below.) $\text {KEY:}$$\underline{\quad\quad}$$\text {pH}$ $\quad$$\underline{\quad\quad}$$\text {Temp.}$

Assuming that each of these possesses a cell wall, which prokaryotes should be expected to be most strongly resistant to plasmolysis in hypertonic environments?

In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures? 1) nucleoid region 2) flagellum 3) endospore 4) fimbriae 5) plasmids

Which of the following are responsible for high levels of O₂ in Earth's atmosphere?

The thermoacidophile, Sulfolobus acidocaldarius lacks peptidoglycan. 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 will lie above pH 7. 4) The optimal pH of its enzymes will lie below pH 7. 5) It could inhabit certain hydrothermal springs. 6) It could inhabit alkaline hot springs.

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf's nonliving, waxy covering, while inhibiting the growth of other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Use only those that apply. 1) nutrient recycler 2) mutualist 3) commensal 4) parasite 5) primary producer

Which statement about the genomes of prokaryotes is correct?

How can prokaryotes be considered to be more successful on Earth than humans?

The following questions refer to structures found in a gram-positive prokaryotic cell. -Which of the following is an important source of endotoxin in gram-negative species?

Modes of obtaining nutrients, used by at least some bacteria, include all of the following except

The following questions refer to structures found in a gram-positive prokaryotic cell. -Not present in all bacteria, this cell covering enables cells that possess it to resist the defenses of host organisms: