Question 1

Which of the following statements best explains why prokaryotes are considered the most abundant group of organisms on Earth?

Accepted Answer

They occupy virtually every habitat, including extreme environments.

Question 2

Which structural feature is found in both Bacteria and Archaea but NOT in Eukarya?

Accepted Answer

Lack of a nucleus

Question 3

A bacterium is observed to be rod-shaped. What is the correct term for this shape?

Accepted Answer

Bacillus

Question 4

Which of the following is a key difference between the cell walls of Bacteria and Archaea?

Accepted Answer

Bacteria have cell walls made of peptidoglycan, while Archaea lack peptidoglycan.

Question 5

Which process allows bacteria to sense their population density and coordinate gene expression, such as toxin production or biofilm formation?

Accepted Answer

Quorum sensing

Question 6

A patient develops a severe infection after a hip replacement. The infection is difficult to treat because the bacteria are protected by a sticky matrix. What is the most likely explanation?

Accepted Answer

The bacteria are forming a biofilm.

Question 7

Which of the following best describes the function of a bacterial endospore?

Accepted Answer

To protect the bacterial genome during harsh conditions

Question 8

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

Accepted Answer

Chemoautotrophy

Question 9

Which of the following is a mutualistic relationship involving prokaryotes?

Accepted Answer

E. coli producing vitamin K in the human gut

Question 10

Which adaptation allows some Archaea to survive in extremely hot environments such as hot springs?

Accepted Answer

Specialized enzymes that function at high temperatures

Question 11

Which of the following statements about prokaryotic flagella is TRUE?

Accepted Answer

Prokaryotic flagella are solid and rotate like a wheel.

Question 12

Which of the following best describes a facultative anaerobe?

Accepted Answer

An organism that can switch between aerobic and anaerobic respiration

Question 13

Which of the following is a common misconception about the classification of prokaryotes?

Accepted Answer

That Gram staining alone is sufficient for accurate classification

Question 14

A scientist discovers a new microorganism living in a highly acidic hot spring. Which domain is this organism most likely to belong to?

Accepted Answer

Archaea

Question 15

Which of the following is NOT a typical shape of prokaryotic cells?

Accepted Answer

Cuboidal

Question 16

Which of the following best explains why endospores are a challenge in food safety?

Accepted Answer

They can survive harsh conditions and later germinate, causing toxin accumulation.

Question 17

Which of the following is a real-world example of a biofilm causing a medical problem?

Accepted Answer

Dental plaque leading to tooth decay

Question 18

Which of the following is a distinguishing feature of Archaea compared to Bacteria?

Accepted Answer

Unique membrane lipids not found in Bacteria

Question 19

Which of the following best describes the role of quorum sensing in bacterial populations?

Accepted Answer

It enables bacteria to coordinate activities such as toxin production when population density is high.

Question 20

Which of the following is a correct statement about the evolutionary relationships among the three domains of life?

Accepted Answer

Archaea and Eukarya are more closely related to each other than either is to Bacteria.

ch 20

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