Q: Which of the following equations correctly represents the overall process of aerobic cellular respiration in bacteria?

$$C_6H_{12}O_6$ + 6\ \mathrm{O}_2 \rightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} + \text{energy}$$

Question 1

Which of the following best describes a microorganism as introduced in the first lecture?

Accepted Answer

Any living organism that is too small to be seen without magnification, including bacteria, archaea, fungi, protozoa, and viruses.

Question 2

A laboratory is classified as Biosafety Level 2 (BSL-2). Which of the following practices is most appropriate for this level?

Accepted Answer

Handling moderate-risk agents with limited access, using gloves and lab coats, and employing procedures to minimize splashes or aerosols.

Question 3

During a Gram stain procedure, a student forgets to add the iodine mordant. What is the most likely result when observing Gram-positive bacteria under the microscope?

Accepted Answer

The cells will appear pink/red because the crystal violet is not fixed and is washed out by the alcohol, allowing the safranin counterstain to dominate.

Question 4

Which of the following is a unique feature of prokaryotic cells compared to eukaryotic cells?

Accepted Answer

DNA located in a nucleoid region without a surrounding membrane.

Question 5

A patient is diagnosed with a bacterial infection. The bacteria are found to have a thick peptidoglycan layer and no outer membrane. Which type of bacteria is most likely responsible?

Accepted Answer

Gram-positive bacteria

Question 6

Which of the following equations correctly represents the overall process of aerobic cellular respiration in bacteria?

Accepted Answer

$$C_6H_{12}O_6$ + 6\ \mathrm{O}_2 ightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 7

A bacterium is found to grow equally well in the presence or absence of oxygen. Which term best describes its oxygen requirements?

Accepted Answer

Facultative anaerobe

Question 8

Which of the following best explains why exponential (log) phase is the most appropriate for measuring the generation time of a bacterial culture?

Accepted Answer

Cells are dividing at a constant and maximum rate, resulting in a straight line when plotted on a logarithmic scale.

Question 9

A hospital is trying to control the spread of a bacterial pathogen. Which of the following methods would be most effective for sterilizing heat-sensitive medical instruments?

Accepted Answer

Ethylene oxide gas sterilization

Question 10

Which of the following best describes the function of DNA polymerase during bacterial DNA replication?

Accepted Answer

Adds nucleotides to the growing DNA strand in the 5' to 3' direction

Question 11

A scientist introduces a plasmid carrying an antibiotic resistance gene into a bacterial cell. Which process is being utilized?

Accepted Answer

Transformation

Question 12

Which of the following is a key difference between the lytic and lysogenic cycles of bacteriophage infection?

Accepted Answer

The lytic cycle results in immediate destruction of the host cell, while the lysogenic cycle integrates the phage DNA into the host genome and can remain dormant.

Question 13

A patient is infected with a virus that has a single-stranded RNA genome and uses reverse transcriptase. Which type of virus is this?

Accepted Answer

Retrovirus

Question 14

Which of the following best describes herd immunity?

Accepted Answer

Protection of susceptible individuals in a population when a sufficient proportion is immune, reducing the spread of disease.

Question 15

A patient is prescribed a drug that inhibits peptidoglycan synthesis. Which type of microorganism will this drug most likely affect?

Accepted Answer

Bacteria

Question 16

Which of the following is the best example of a nosocomial infection?

Accepted Answer

A patient develops pneumonia after being admitted to the hospital for surgery.

Question 17

Which of the following best describes the role of T helper cells in adaptive immunity?

Accepted Answer

They activate B cells and cytotoxic T cells by releasing cytokines.

Question 18

Which of the following is a major environmental role of microorganisms?

Accepted Answer

They recycle nutrients such as carbon and nitrogen through biogeochemical cycles.

Question 19

A patient is given a broad-spectrum antibiotic and subsequently develops a Clostridioides difficile infection. What is the most likely explanation for this outcome?

Accepted Answer

The antibiotic disrupted the normal microbiota, reducing competition and allowing C. difficile to proliferate.

Question 20

Which of the following best describes the difference between innate and adaptive immunity?

Accepted Answer

Innate immunity provides immediate, non-specific defense, while adaptive immunity develops more slowly and is specific to particular antigens.

General Microbiology: Course Syllabus and Topic Overview

Study Guide - Practice Questions

Study Guide - Flashcards