Question 1

Which of the following best describes the main advantage of the three-domain system over the five-kingdom system?

Accepted Answer

It reflects evolutionary relationships based on rRNA nucleotide sequences.

Question 2

Which of the following is NOT a characteristic used to differentiate the domains Bacteria, Archaea, and Eukarya?

Accepted Answer

Ability to undergo photosynthesis

Question 3

A scientist isolates a microorganism with the following characteristics: no nucleus, cell wall without peptidoglycan, and membrane lipids with branched carbon chains attached to glycerol by ether linkage. To which domain does this organism most likely belong?

Accepted Answer

Archaea

Question 4

Which of the following statements about the endosymbiont theory is correct?

Accepted Answer

Mitochondria and chloroplasts originated from prokaryotic cells living inside ancestral eukaryotic cells.

Question 5

Which of the following best explains why binomial nomenclature is preferable to common names in scientific communication?

Accepted Answer

It provides a universal, standardized system for naming organisms.

Question 6

A clinical laboratory is trying to identify an unknown bacterium. Which of the following methods would be LEAST useful if the bacterium lacks a cell wall?

Accepted Answer

Gram staining

Question 7

Which of the following is the correct order of taxonomic hierarchy from broadest to most specific?

Accepted Answer

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

Question 8

Which of the following laboratory techniques is used to determine the presence of specific antibodies in a patient’s serum, such as in HIV testing?

Accepted Answer

Indirect ELISA

Question 9

A researcher uses PCR to amplify DNA from an unknown microorganism that cannot be cultured. Which of the following best describes the purpose of this technique?

Accepted Answer

To produce enough DNA for identification by gel electrophoresis

Question 10

Which of the following statements about nucleic acid hybridization is correct?

Accepted Answer

A high degree of hybridization indicates that two organisms are closely related.

Question 11

Which of the following is a key difference between classification and identification in microbiology?

Accepted Answer

Classification involves grouping organisms based on evolutionary relationships, while identification matches an unknown organism to known groups.

Question 12

Which of the following best describes a 'strain' in microbiology?

Accepted Answer

Genetically different cells within a clone

Question 13

Which of the following methods can be used to differentiate between strains of the same bacterial species in an outbreak investigation?

Accepted Answer

Phage typing

Question 14

Which of the following is a defining feature of the domain Eukarya?

Accepted Answer

Membrane-bound nucleus

Question 15

A dichotomous key is best described as:

Accepted Answer

A tool that uses a series of paired statements to identify organisms

Question 16

Which of the following is true regarding viruses in biological classification?

Accepted Answer

They are not part of any domain because they are not composed of cells.

Question 17

Which of the following is a real-world application of fatty acid methyl ester (FAME) analysis in microbiology?

Accepted Answer

Identifying bacterial species based on their unique fatty acid profiles

Question 18

Which of the following statements about Bergey’s Manual is correct?

Accepted Answer

It is used to classify and identify bacteria and archaea based on various characteristics.

Question 19

Which of the following best describes the molecular clock concept in phylogenetics?

Accepted Answer

Mutations accumulate in a genome at a constant rate, allowing estimation of evolutionary divergence.

Question 20

Which of the following is a practical use of flow cytometry in microbiology?

Accepted Answer

Identifying bacteria in a fluid sample based on differences in fluorescence without culturing

Classification of Microorganisms: Taxonomy, Phylogeny, and Identification Methods

Study Guide - Practice Questions

Study Guide - Flashcards