Question 1

Which of the following best describes the purpose of scientific binomial nomenclature in microbiology?

Accepted Answer

To assign each organism a unique two-part name for efficient identification and communication.

Question 2

A clinical sample is found to contain Gram-negative, rod-shaped bacteria that ferment lactose but cannot use citric acid as their sole carbon source. According to a dichotomous key, which genus is most likely present?

Accepted Answer

Escherichia

Question 3

Which molecular technique is used to determine evolutionary relationships among prokaryotes by comparing sequences of ribosomal RNA?

Accepted Answer

Ribotyping

Question 4

A bacterium is classified as a member of the phylum Actinomycetota. Which characteristic is most likely true?

Accepted Answer

It has a high G+C content and produces antibiotics.

Question 5

Which equation correctly represents the calculation of DNA base composition in bacteria?

Accepted Answer

$$G+C + A+T = 100\%$$

Question 6

Which of the following is a major criterion used in Bergey's Manual for bacterial identification?

Accepted Answer

Cell wall composition

Question 7

A patient presents with symptoms of botulism. Which bacterial genus is most likely responsible, and what is a key identifying feature?

Accepted Answer

Clostridium; obligate anaerobic, endospore-producing rods

Question 8

Which of the following best describes the function of nucleic acid hybridization in bacterial identification?

Accepted Answer

It measures the ability of DNA strands from different organisms to hybridize, indicating relatedness.

Question 9

Which pathogenic bacterium is transmitted by deer ticks and causes Lyme disease?

Accepted Answer

Borrelia burgdorferi

Question 10

Which of the following is a distinguishing feature of Gram-positive bacteria with low G+C content?

Accepted Answer

They include endospore-producing rods such as Bacillus and Clostridium.

Question 11

Which of the following is true about the genus Mycoplasma?

Accepted Answer

It lacks a cell wall and is resistant to many antimicrobial agents.

Question 12

Which of the following is a zoonotic disease caused by Brucella, and what is a common route of transmission?

Accepted Answer

Brucellosis; animal contact or unpasteurized milk/products

Question 13

Which method would be most appropriate for identifying an unknown bacterium that cannot be cultured?

Accepted Answer

Nucleic Acid Amplification Test (PCR)

Question 14

Which of the following is a correct sequence for taxonomic hierarchy in prokaryotes?

Accepted Answer

Species → Genus → Family → Order → Class → Phylum → Kingdom → Domain

Question 15

Which phylum includes bacteria that are obligate intracellular parasites and lack peptidoglycan in their cell wall?

Accepted Answer

Chlamydiota

Question 16

A patient is diagnosed with pneumonia caused by a wall-less, pleomorphic bacterium. Which genus is most likely responsible?

Accepted Answer

Mycoplasma

Question 17

Which of the following is a characteristic of Deinococcus radiodurans?

Accepted Answer

It is highly resistant to radiation due to unique DNA repair mechanisms.

Question 18

Which equation would you use to calculate the percent similarity between two rRNA sequences for constructing a cladogram?

Accepted Answer

$$	ext{Percent similarity} = \frac{	ext{Number of matching bases}}{	ext{Total number of bases}} 	imes 100\%$$

Question 19

Which of the following is a defining feature of the phylum Cyanobacteria?

Accepted Answer

They are oxygenic photosynthetic bacteria.

Question 20

Which genus is responsible for causing food poisoning and is an endospore-producing rod?

Accepted Answer

Bacillus

Classification and Identification of Bacteria: Taxonomy, Methods, and Major Groups

Study Guide - Practice Questions

Study Guide - Flashcards