Question 1

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

Accepted Answer

Their outer membrane contains lipopolysaccharides that act as a barrier to many antibiotics.

Question 2

A scientist discovers a prokaryote living in a hot spring with temperatures above 80°C. The organism lacks peptidoglycan in its cell wall and initiates protein synthesis with methionine. To which group does this organism most likely belong?

Accepted Answer

Archaea

Question 3

Which process allows bacteria to acquire new genetic traits, such as antibiotic resistance, by direct transfer of plasmids through a sex pilus?

Accepted Answer

Conjugation

Question 4

A patient is infected with a bacterium that survives in the presence or absence of oxygen by switching between aerobic respiration and fermentation. This bacterium is best classified as a:

Accepted Answer

Facultative anaerobe

Question 5

Which equation correctly represents the process of nitrogen fixation performed by certain prokaryotes?

Accepted Answer

$$\mathrm{N_2$ + 3H_2 \rightarrow 2NH_3}$$

Question 6

Which of the following best describes the role of fimbriae in prokaryotes?

Accepted Answer

They facilitate attachment to surfaces and other cells.

Question 7

A researcher is studying a bacterium that can use light for energy and organic compounds as a carbon source. Which nutritional mode does this bacterium exhibit?

Accepted Answer

Photoheterotrophy

Question 8

Which of the following is NOT a typical target of antibiotics in bacterial cells?

Accepted Answer

Mitochondrial function

Question 9

Which of the following best explains why endospores contribute to the pathogenicity of certain bacteria?

Accepted Answer

They enable bacteria to survive extreme conditions and evade host defenses.

Question 10

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

Accepted Answer

It helps with digestion, vitamin production, and immune system development.

Question 11

Which group of bacteria is believed to be the ancestor of mitochondria according to the endosymbiotic theory?

Accepted Answer

Alpha-proteobacteria

Question 12

A bacterium is found living in a salt lake with extremely high salinity. To which group does it most likely belong?

Accepted Answer

Halophiles

Question 13

Which of the following best describes mutualism in a symbiotic relationship?

Accepted Answer

Both organisms benefit from the interaction.

Question 14

Which of the following is a real-world application of bacteria in biotechnology?

Accepted Answer

Using E. coli for gene cloning

Question 15

A scientist observes a bacterial colony that appears purple after Gram staining. What can be inferred about the cell wall structure of these bacteria?

Accepted Answer

They have a thick peptidoglycan layer and no outer membrane.

Question 16

Which of the following best describes the genetic organization of prokaryotes?

Accepted Answer

They have a single circular chromosome and may contain plasmids.

Question 17

Which of the following scenarios best illustrates horizontal gene transfer in bacteria?

Accepted Answer

A bacterium acquires a gene for antibiotic resistance from a virus (bacteriophage).

Question 18

Which of the following is a correct pairing of prokaryotic nutritional mode and example?

Accepted Answer

Chemoautotroph – nitrogen-fixing bacteria

Question 19

Which of the following best explains how antibiotic resistance can spread rapidly in a hospital setting?

Accepted Answer

Horizontal gene transfer allows resistance genes to move between different bacterial species.

Question 20

Which of the following best describes the function of a capsule in bacterial cells?

Accepted Answer

It helps bacteria attach to surfaces and evade the immune system.

Prokaryotes: Key Concepts and Study Guidance

Study Guide - Practice Questions

Study Guide - Flashcards