Question 1

Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall
2)  presence of plasma membrane
3)  lack of a nuclear envelope
4)  identical rRNA sequences

Accepted Answer

A)   1 only
B)   3 only
C)   1 and 3
D)   2 and 3
E)   2 and 4F) A) and C)
G) C) and D)

Question 2

Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?

Accepted Answer

A)   skin commensalist
B)   pathogen
C)   bioluminescent bacteria in fish
D)   gut mutualist
E)   decomposerF) None of the above
G) A) and B)

Question 3

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.

Accepted Answer

A)   endospore
B)   sex pilus
C)   cell wall
D)   capsuleE) A) and B)
F) A) and C)

Question 4

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

Accepted Answer

A)   extreme halophiles
B)   extreme thermophiles
C)   methanogens
D)   cyanobacteria
E)   nitrogen-fixing bacteria that live in root nodulesF) A) and B)
G) B) and E)

Question 5

Use the information in the following paragraph to answer the next few questions.
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 phagocytes, 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.
-This bacterium's ability to survive in a human who is taking penicillin pills may be due to the presence of which of the following? 1. penicillin-resistance genes
2)  a secretory system that removes penicillin from the cell
3)  a gram-positive cell wall
4)  a gram-negative cell wall
5)  an endospore

Accepted Answer

A)   1 or 5
B)   2 or 3
C)   4 or 5
D)   2, 3, or 5
E)   2, 4, or 5F) B) and E)
G) All of the above

Question 6

Use the information in the following paragraph to answer the next few questions.
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 phagocytes, 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.
-What should be true of the cell wall of this bacterium?

Accepted Answer

A)   Its innermost layer is composed of a phospholipid bilayer.
B)   After it has been subjected to Gram staining, the cell should remain purple.
C)   It has an outer membrane of lipopolysaccharide.
D)   It is mostly composed of a complex, cross-linked polysaccharide.
E)   Two of the responses above are correct.F) None of the above
G) A) and B)

Question 7

If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

Accepted Answer

A)   transduction.
B)   binary fission.
C)   conjugation.
D)   transformation.
E)   meiosis.F) B) and E)
G) B) and D)

Question 8

Which of the following is least associated with the others?

Accepted Answer

A)   horizontal gene transfer
B)   genetic recombination
C)   conjugation
D)   transformation
E)   binary fissionF) C) and D)
G) A) and B)

Question 9

Which of the following is the correct sequence of events in the origin of life? I. formation of protobionts
II)  synthesis of organic monomers
III)  synthesis of organic polymers
IV)  formation of DNA-based genetic systems

Accepted Answer

A)   I, II, III, IV
B)   I, III, II, IV
C)   II, III, I, IV
D)   II, III, IV, IE) None of the above
F) A) and D)

Exam 24: Early Life and the Diversification of Prokaryotes

Which of the following is least associated with the others?

Correct Answer
verified

If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

Correct Answer
verified

Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?

Correct Answer
verified

Which of the following is the correct sequence of events in the origin of life? I. formation of protobionts II) synthesis of organic monomers III) synthesis of organic polymers IV) formation of DNA-based genetic systems

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall 2) presence of plasma membrane 3) lack of a nuclear envelope 4) identical rRNA sequences

Correct Answer
verified

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.

Correct Answer
verified

Exam 24: Early Life and the Diversification of Prokaryotes

Which of the following is least associated with the others?

Correct AnswerverifiedShow Answer

If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

Correct AnswerverifiedShow Answer

Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?

Correct AnswerverifiedShow Answer

Which of the following is the correct sequence of events in the origin of life? I. formation of protobionts II) synthesis of organic monomers III) synthesis of organic polymers IV) formation of DNA-based genetic systems

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall 2) presence of plasma membrane 3) lack of a nuclear envelope 4) identical rRNA sequences

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified