Exam 24: Early Life and the Diversification of Prokaryotes

Gram-variable prokaryotes are, sometimes, those without any peptidoglycan. Which two species are most likely to be archaeans?

The first genes on Earth were probably

Prokaryotes' essential genetic information is located in the

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)?

Plantlike photosynthesis that releases O2 occurs in

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

Which two species might be expected to cooperate metabolically, perhaps forming a biofilm wherein one species surrounds cells of the other species?

The following questions refer to Figure 24.1. 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 24.1 -Which term best describes what has occurred among the experimental populations of cells over this eight-year period?

Photoautotrophs use

Which of the following is a defining characteristic that all protobionts had in common?

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?

Which statement about the genomes of prokaryotes is correct?

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 energy from light

Which statement about the domain Archaea is true?

Which of the following is an important source of endotoxin in gram-negative species?

The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of

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 structure(s)? 1. nucleoid region 2) endospore 3) fimbriae 4) plasmids

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

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 questions. Figure 24.2 -What is occurring at Time C that is decreasing the DNA content?

Certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This evidence supports the claim that