Question 1

Which of the following is the primary basis for modern prokaryotic classification?

Accepted Answer

Genetic relatedness of rRNA sequences

Question 2

Which domain includes organisms that are known for surviving in extreme environments such as high salinity or temperature?

Accepted Answer

Archaea

Question 3

A bacterium that is classified as a 'coccus' would most likely appear as which of the following under a microscope?

Accepted Answer

Spherical

Question 4

Which group of bacteria is considered to represent the earliest branch of bacterial evolution and is autotrophic?

Accepted Answer

Aquifex

Question 5

Which of the following phototrophic bacteria is responsible for oxygenic photosynthesis and is closely related to chloroplasts?

Accepted Answer

Cyanobacteria

Question 6

What is the general chemical equation for oxygenic photosynthesis performed by cyanobacteria?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 7

Which of the following is a distinguishing feature of Mycoplasma compared to other bacteria?

Accepted Answer

Lack of a cell wall

Question 8

Which genus of bacteria is known for producing Bt toxin, used as a biological pesticide?

Accepted Answer

Bacillus thuringiensis

Question 9

Which class of Proteobacteria includes many important human pathogens such as Escherichia and Salmonella?

Accepted Answer

Gammaproteobacteria

Question 10

A patient presents with symptoms of cholera. Which genus of bacteria is most likely responsible?

Accepted Answer

Vibrio

Question 11

Which of the following bacteria is an obligate intracellular pathogen and is the most common sexually transmitted bacterium in the United States?

Accepted Answer

Chlamydia

Question 12

Spirochetes are characterized by which of the following features?

Accepted Answer

Corkscrew motility

Question 13

Why are bacteria classified in the same domain despite their diverse oxygen tolerances, sizes, shapes, and nutritional requirements?

Accepted Answer

They share a common genetic ancestry based on rRNA sequences

Question 14

Which of the following is a deeply branching bacterium believed to resemble early life forms and is autotrophic?

Accepted Answer

Aquifex

Question 15

Which of the following genera is classified as high G+C Gram-positive bacteria and is known for producing antibiotics?

Accepted Answer

Streptomyces

Question 16

A bacterium is described as 'pleomorphic.' What does this mean?

Accepted Answer

It can change its shape and size

Question 17

Which of the following is NOT a typical arrangement of cocci?

Accepted Answer

Spirals (spirilla)

Question 18

Which of the following is a correct match between a bacterial genus and a disease it causes?

Accepted Answer

Yersinia – Plague

Question 19

Which of the following is a characteristic of Gram-negative Proteobacteria?

Accepted Answer

Largest and most diverse group of bacteria

Question 20

Which of the following is a facultative anaerobe commonly found in the human gut and is oxidase negative?

Accepted Answer

Escherichia coli

Chapter 11: Characterizing and Classifying Prokaryotes

Study Guide - Practice Questions