Question 1

Which of the following statements best explains why salt is commonly used as a preservative for foods?

Accepted Answer

Salt causes prokaryotic cells to undergo plasmolysis, slowing their reproduction.

Question 2

A bacterium is observed to have a thick peptidoglycan layer and stains purple with Gram stain. Which of the following is most likely true about this bacterium?

Accepted Answer

It is Gram-positive and more susceptible to antibiotics that target cell wall synthesis.

Question 3

Which structure allows bacteria to survive extreme conditions such as high heat or desiccation for centuries?

Accepted Answer

Endospore

Question 4

A scientist discovers a prokaryote living in a hot spring at 90°C. Which group is this organism most likely to belong to?

Accepted Answer

Archaea, specifically an extreme thermophile

Question 5

Which of the following best describes the process of bacterial conjugation?

Accepted Answer

DNA is transferred from a donor to a recipient cell through a pilus, often involving the F factor.

Question 6

Which nutritional mode is correctly matched with its energy and carbon sources?

Accepted Answer

Photoautotroph: Light as energy source, $$CO_2 as $$carbon source

Question 7

Which of the following is a key reason why antibiotics can target bacterial cells without harming human cells?

Accepted Answer

Bacterial cell walls contain peptidoglycan, which is absent in human cells.

Question 8

A patient develops a chronic infection on a medical implant that is resistant to antibiotics. Which prokaryotic adaptation most likely contributes to this resistance?

Accepted Answer

Formation of a biofilm

Question 9

Which of the following best describes the role of the F factor in bacterial conjugation?

Accepted Answer

It enables the formation of pili and the transfer of DNA between cells.

Question 10

Which metabolic process is unique to certain prokaryotes and is essential for the nitrogen cycle in ecosystems?

Accepted Answer

Nitrogen fixation: $$N_2$$ \rightarrow $$NH_3$$

Question 11

Which of the following statements about R plasmids is correct?

Accepted Answer

They carry genes for antibiotic resistance and can be transferred between bacteria.

Question 12

A bacterium is found to be an obligate anaerobe. Which of the following environments would be most suitable for its growth?

Accepted Answer

A deep mud layer with no oxygen

Question 13

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

Accepted Answer

They have an outer membrane that protects against many antibiotics.

Question 14

Which of the following is NOT a function of the bacterial capsule?

Accepted Answer

Carrying out nitrogen fixation

Question 15

Which of the following scenarios best illustrates horizontal gene transfer?

Accepted Answer

A bacterium acquires antibiotic resistance by receiving a plasmid from another bacterium.

Question 16

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

Accepted Answer

Archaea have membrane lipids with some branched hydrocarbons.

Question 17

Which of the following best describes the genetic material of most prokaryotes?

Accepted Answer

A single circular chromosome located in the nucleoid region

Question 18

A researcher observes a prokaryote moving toward a chemical attractant. Which term best describes this behavior?

Accepted Answer

Chemotaxis

Question 19

Which of the following is a real-world consequence of biofilm formation by prokaryotes?

Accepted Answer

Chronic, antibiotic-resistant infections on medical devices

Question 20

Which of the following best describes the process of transduction in bacteria?

Accepted Answer

A bacteriophage transfers DNA from one bacterium to another.

Bacteria and Archaea: Structure, Function, and Diversity

Study Guide - Practice Questions

Study Guide - Flashcards