Question 1

Which of the following statements best explains why prokaryotes exhibit such large genetic diversity?

Accepted Answer

Rapid reproduction, mutation, and genetic recombination through horizontal gene transfer all contribute to their genetic diversity.

Question 2

A scientist isolates a prokaryotic cell with a thick peptidoglycan layer in its cell wall. After performing a Gram stain, what color will the cell most likely appear, and why?

Accepted Answer

Purple, because the thick peptidoglycan layer retains the crystal violet stain.

Question 3

Which metabolic process is responsible for converting atmospheric nitrogen ($$N_2) $$into a form usable by living organisms, and which group of prokaryotes is especially important for this process?

Accepted Answer

Nitrogen fixation; certain bacteria and cyanobacteria

Question 4

Which of the following best describes the difference between prokaryotic and eukaryotic DNA organization?

Accepted Answer

Prokaryotes have a single circular chromosome and plasmids in the nucleoid region, while eukaryotes have multiple linear chromosomes inside a nucleus.

Question 5

A patient is infected with a Gram-negative bacterium. Which property of the cell wall makes this bacterium more resistant to antibiotics like penicillin?

Accepted Answer

An outer phospholipid bilayer that prevents antibiotic penetration.

Question 6

Which of the following is NOT a method of horizontal gene transfer in prokaryotes?

Accepted Answer

Binary fission

Question 7

A bacterium is found living in a hypersaline lake. Which domain is it most likely to belong to, and what is the term for organisms that thrive in such environments?

Accepted Answer

Archaea; halophiles

Question 8

Which of the following best describes the role of cyanobacteria in Earth's history?

Accepted Answer

They were the first organisms to perform photosynthesis that produced $$O_2$$, leading to increased atmospheric oxygen.

Question 9

Which of the following statements about Koch's postulates is correct?

Accepted Answer

They provide a systematic method to link a specific microbe to a specific infectious disease.

Question 10

A prokaryote is observed moving toward a chemical stimulus. Which term best describes this behavior, and what structure is most commonly involved?

Accepted Answer

Chemotaxis; flagellum

Question 11

Which of the following is a real-world application of prokaryotes in environmental science?

Accepted Answer

Using bacteria for bioremediation to degrade oil pollutants.

Question 12

Which of the following statements about Archaea is true?

Accepted Answer

Archaea can live in extreme environments such as high temperature and high salinity.

Question 13

Which of the following is a correct pairing of prokaryotic metabolic type and its energy source?

Accepted Answer

Chemoheterotroph; organic molecules

Question 14

A bacterium survives boiling temperatures and remains dormant for years. Which structure is responsible for this resilience?

Accepted Answer

Endospore

Question 15

Which of the following is NOT a characteristic shared by all three domains of life?

Accepted Answer

Presence of membrane-bound organelles

Question 16

Which process allows bacteria to acquire new genetic material from their environment, and what is the term for this process?

Accepted Answer

Transformation; uptake of DNA from the environment

Question 17

Which of the following best explains why Gram-negative bacteria are generally more resistant to antibiotics than Gram-positive bacteria?

Accepted Answer

Gram-negative bacteria have an outer membrane that restricts drug entry.

Question 18

Which of the following is a correct example of a beneficial prokaryote and its function?

Accepted Answer

Cyanobacteria; oxygen production through photosynthesis

Question 19

A researcher discovers a prokaryote that can grow with or without oxygen. What term best describes this organism?

Accepted Answer

Facultative anaerobe

Bacteria and Archaea: Structure, Diversity, and Roles in Biology

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