Question 1

Which of the following statements best explains why eukaryotes and archaea are more closely related to each other than either is to bacteria, according to rRNA gene analysis?

Accepted Answer

Both eukaryotes and archaea share a more recent common ancestor, as shown by similarities in their rRNA genes.

Question 2

Horizontal gene transfer (HGT) has played a significant role in the evolution of prokaryotes. Which of the following is NOT a mechanism of HGT?

Accepted Answer

Binary fission

Question 3

A researcher discovers a prokaryote that thrives in extremely salty environments. Which group is this organism most likely to belong to?

Accepted Answer

Extreme halophiles

Question 4

Which of the following best describes the structure and function of a bacterial capsule?

Accepted Answer

A sticky layer of polysaccharide or protein that enables adherence to substrates and protects against dehydration.

Question 5

Which metabolic mode describes an organism that uses light as an energy source and CO$_2$ as a carbon source?

Accepted Answer

Photoautotroph

Question 6

A bacterium is found to survive only in the absence of oxygen and dies when exposed to it. Which term best describes this organism?

Accepted Answer

Obligate anaerobe

Question 7

Which of the following is a key difference between the cell walls of bacteria and archaea?

Accepted Answer

Bacterial cell walls contain peptidoglycan, while archaeal cell walls do not.

Question 8

Which process involves the uptake of naked DNA fragments from the environment by a prokaryotic cell?

Accepted Answer

Transformation

Question 9

A soil sample contains bacteria that can convert atmospheric nitrogen (N$_2$) into ammonia (NH$_3$). What is this process called?

Accepted Answer

Nitrogen fixation

Question 10

Which of the following best explains why antibiotics that target peptidoglycan synthesis are effective against bacteria but not archaea or eukaryotes?

Accepted Answer

Only bacteria have peptidoglycan in their cell walls.

Question 11

Which of the following is a real-world example of horizontal gene transfer impacting human health?

Accepted Answer

The spread of antibiotic resistance genes among pathogenic bacteria.

Question 12

Which group of bacteria is the likely ancestor of chloroplasts, according to the endosymbiotic theory?

Accepted Answer

Cyanobacteria

Question 13

A patient is diagnosed with a bacterial infection caused by a helical, gram-negative bacterium. Which group is the pathogen most likely from?

Accepted Answer

Spirochetes

Question 14

Which of the following best describes the genetic material in a typical prokaryotic cell?

Accepted Answer

A single circular chromosome and plasmids, not enclosed by a membrane

Question 15

Which of the following is a correct pairing of a prokaryotic group and a disease it causes?

Accepted Answer

Spirochetes – Syphilis

Question 16

Which of the following best explains why prokaryotes can adapt rapidly to new environments?

Accepted Answer

They reproduce rapidly and can exchange genetic material through horizontal gene transfer.

Question 17

A prokaryote that uses inorganic chemicals such as H$_2$S for energy and CO$_2$ as a carbon source is classified as a:

Accepted Answer

Chemoautotroph

Question 18

Which of the following statements about endospores is correct?

Accepted Answer

Endospores are metabolically inactive structures that allow bacteria to survive extreme conditions.

Question 19

Which of the following is a unique feature of archaea compared to bacteria?

Accepted Answer

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

Question 20

A bacterium is found to have a sticky outer layer that is not well organized. What is this structure called, and what is its function?

Accepted Answer

Slime layer; enables adherence to substrates and protects against dehydration

Prokaryotic Diversity, Evolution, and the Tree of Life

Study Guide - Practice Questions

Study Guide - Flashcards