Question 1

Which of the following statements best describes a key difference between Bacteria and Archaea?

Accepted Answer

Bacteria have peptidoglycan in their cell walls, while Archaea do not.

Question 2

Which metabolic strategy is used by prokaryotes that obtain energy from inorganic chemicals and carbon from carbon dioxide?

Accepted Answer

Chemolithoautotrophy

Question 3

A patient is diagnosed with a bacterial infection that produces toxins attacking the gut lining, often treated with a fecal transplant. Which bacterium is most likely responsible?

Accepted Answer

Clostridioides difficile

Question 4

Which of the following is NOT a mechanism of lateral (horizontal) gene transfer in prokaryotes?

Accepted Answer

Binary fission

Question 5

Which feature is unique to Archaea and not found in Bacteria?

Accepted Answer

Histones associated with DNA

Question 6

During the Great Oxygenation Event, which process performed by prokaryotes was primarily responsible for the increase in atmospheric oxygen?

Accepted Answer

Oxygenic photosynthesis by cyanobacteria

Question 7

Which of the following best explains why lateral gene transfer complicates the construction of prokaryotic phylogenies?

Accepted Answer

Genes can be exchanged between unrelated lineages, making it difficult to trace evolutionary relationships using a single gene.

Question 8

A bacterium that uses light for energy and organic compounds as a carbon source is classified as a:

Accepted Answer

Photoheterotroph

Question 9

Which of the following is a real-world example of a mutualistic relationship involving prokaryotes?

Accepted Answer

Sulfur-eating bacteria living in Riftia pachyptila tube worms, providing carbon to the worm

Question 10

Which of the following statements about the human microbiome is TRUE?

Accepted Answer

The composition of the microbiome can affect how individuals respond to certain medications.

Question 11

Which of the following best describes the process of nitrogen fixation?

Accepted Answer

Conversion of atmospheric $N_2$ into ammonia ($NH_3$) by certain prokaryotes

Question 12

Which of the following is a correct statement about binary fission in prokaryotes?

Accepted Answer

It results in two genetically identical daughter cells, barring mutations or gene transfer.

Question 13

A Gram-negative bacterium is characterized by which of the following features?

Accepted Answer

A thin peptidoglycan layer and an outer membrane

Question 14

Which of the following is a plausible consequence of excessive antibiotic use in early childhood?

Accepted Answer

Permanent alteration of the diversity of the gut microbiome

Question 15

Which of the following best explains why some bacteria are able to survive in extreme environments such as high temperature or acidity?

Accepted Answer

They possess unique adaptations in their cell membranes and enzymes that allow stability under extreme conditions.

Question 16

Which of the following is a real-world application of prokaryotic metabolism in environmental remediation?

Accepted Answer

Using bacteria to degrade toxic chemicals or plastics into neutral compounds

Question 17

Which of the following statements about the Three-Domain Hypothesis is correct?

Accepted Answer

It proposes that all life is divided into Bacteria, Archaea, and Eukarya.

Question 18

A scientist discovers a microorganism with a single circular chromosome, no membrane-bound organelles, and a cell wall lacking peptidoglycan. Which domain does this organism most likely belong to?

Accepted Answer

Archaea

Question 19

Which of the following is a correct example of how the microbiome can influence human health?

Accepted Answer

Certain gut bacteria can metabolize drugs, making them less effective for some patients.

Question 20

Which of the following best describes the role of lateral gene transfer in the evolution of prokaryotes?

Accepted Answer

It allows for the rapid acquisition of new traits, such as antibiotic resistance, from unrelated organisms.

Prokaryotes: Bacteria & Archaea – Structure, Classification, and Biology

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