Question 1

Which of the following best explains why Mycobacterium species are acid-fast when stained?

Accepted Answer

Their cell walls contain a high concentration of mycolic acids, making them resistant to decolorization by acid-alcohol.

Question 2

A microbiologist is using a brightfield microscope to observe stained bacteria. Which of the following best describes the path of light through the microscope?

Accepted Answer

Light passes through the condenser, then the specimen, then the objective lens, then the ocular lens, and finally to the eye.

Question 3

Which of the following statements about ATP is correct?

Accepted Answer

ATP stores and transfers energy between catabolic and anabolic reactions.

Question 4

A bacterial culture is growing in a medium with high salt concentration. Only a few colonies are visible after incubation. Which term best describes these bacteria?

Accepted Answer

Halophiles

Question 5

During glycolysis, what is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

$$2$$ ATP and $$2$$ NADH

Question 6

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotes have a nucleus and organelles, prokaryotes do not.

Question 7

A patient is diagnosed with tuberculosis, an infectious disease caused by Mycobacterium tuberculosis. Which staining technique would be most appropriate to identify this organism in a sputum sample?

Accepted Answer

Acid-fast stain

Question 8

Which of the following is a correct statement about the lytic cycle of a bacteriophage?

Accepted Answer

The phage attaches, penetrates, biosynthesizes, assembles, and releases new phages, destroying the host cell.

Question 9

Which of the following best explains why endospores are more resistant to chemical disinfectants than vegetative cells?

Accepted Answer

Endospores contain a tough outer coat and dehydrated core, making them highly resistant.

Question 10

A researcher is testing the effectiveness of a new disinfectant using a use-dilution test. What is the main purpose of this test?

Accepted Answer

To evaluate the effectiveness of the disinfectant in solution against specific microbes.

Question 11

Which of the following best describes the process of binary fission in bacteria?

Accepted Answer

One cell divides to produce two genetically identical cells.

Question 12

Which of the following statements about the Gram stain is correct?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer that retains the crystal violet stain.

Question 13

A scientist is studying a microbe that can grow in the presence or absence of oxygen, but grows better with oxygen. Which term best describes this organism?

Accepted Answer

Facultative anaerobe

Question 14

Which of the following is a correct pairing of a macromolecule and its building block?

Accepted Answer

Lipids – fatty acids

Question 15

Which of the following best describes the role of the electron transport chain (ETC) in cellular respiration?

Accepted Answer

The ETC pumps protons to create a gradient used by ATP synthase to generate ATP.

Question 16

A patient is infected with a virus that integrates its DNA into the host genome and remains dormant for years before reactivating. Which term best describes this type of infection?

Accepted Answer

Latent infection

Question 17

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

Accepted Answer

Mitochondria and chloroplasts originated from ancient bacteria that were engulfed by ancestral eukaryotic cells.

Question 18

Which of the following best describes the difference between sterilization and disinfection?

Accepted Answer

Sterilization destroys all forms of microbial life, while disinfection reduces or eliminates pathogens on surfaces.

Question 19

Which of the following is a correct description of a photoautotroph?

Accepted Answer

An organism that uses light as an energy source and CO$$_2 as a $$carbon source.

Question 20

A hospital is experiencing an outbreak of a new viral disease that is increasing in incidence and was previously unknown. Which term best describes this type of disease?

Accepted Answer

Emerging infectious disease

Microbiology Core Concepts: Mini-Textbook Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards