Question 1

Which of the following structures is found only in eukaryotic cells and not in prokaryotic cells?

Accepted Answer

Mitochondria

Question 2

A microbiologist is studying a bacterium that survives harsh conditions by forming a tough, dormant structure. What is this structure called, and what is its primary function?

Accepted Answer

Endospore; to protect genetic material during extreme conditions

Question 3

Which of the following best describes the difference between Gram-positive and Gram-negative bacterial cell walls?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and no outer membrane

Question 4

A patient is diagnosed with a fungal infection. What is the term for a disease caused by fungi, and what is one benefit fungi provide to humans?

Accepted Answer

Mycosis; production of antibiotics such as penicillin

Question 5

Which of the following statements about viruses is correct?

Accepted Answer

Viruses are obligate intracellular pathogens and typically infect only specific cell types

Question 6

Which of the following is a correct example of a symbiotic relationship where one organism benefits and the other is harmed?

Accepted Answer

Parasitism

Question 7

A researcher is using a Gram stain to differentiate bacteria. Which step in the Gram stain procedure is responsible for decolorizing Gram-negative cells?

Accepted Answer

Application of alcohol or acetone

Question 8

Which of the following best describes the function of bacterial ribosomes compared to eukaryotic ribosomes?

Accepted Answer

Bacterial ribosomes are smaller (70S) and are the target of many antibiotics

Question 9

Which of the following is a correct definition of the median infectious dose ($$ID_{50}$$)?

Accepted Answer

The number of pathogens required to infect 50% of a test population

Question 10

Which of the following statements about exotoxins and endotoxins is correct?

Accepted Answer

Exotoxins are secreted proteins that can cause specific effects, while endotoxins are lipopolysaccharides released from Gram-negative bacteria

Question 11

A patient develops a fever after a bacterial infection. Which of the following best explains how fever occurs in response to infection?

Accepted Answer

Pyrogens stimulate the hypothalamus to raise the body's set point temperature

Question 12

Which of the following best describes herd immunity?

Accepted Answer

Immunity that results when a large portion of a population is immune, reducing disease spread

Question 13

Which of the following is a real-world example of bioremediation using microorganisms?

Accepted Answer

Using bacteria to degrade oil spills in the environment

Question 14

A hospital is concerned about the spread of methicillin-resistant Staphylococcus aureus (MRSA). Which of the following best describes MRSA?

Accepted Answer

A Gram-positive bacterium resistant to methicillin and often other antibiotics

Question 15

Which of the following best describes the purpose of the acid-fast stain?

Accepted Answer

To identify bacteria with waxy cell walls, such as Mycobacterium species

Question 16

Which of the following is a correct statement about the use of broad-spectrum antibiotics?

Accepted Answer

They target a wide range of bacteria, increasing the risk of disrupting normal microbiota

Question 17

A scientist is using a transmission electron microscope (TEM) to study bacteria. What is a key advantage of TEM over light microscopy?

Accepted Answer

TEM provides much higher resolution, allowing visualization of internal cell structures

Question 18

Which of the following best describes quorum sensing in bacteria?

Accepted Answer

A mechanism for bacteria to communicate and coordinate gene expression based on population density

Question 19

Which of the following is a correct definition of a mechanical vector in disease transmission?

Accepted Answer

An organism that transmits a pathogen by physically carrying it on its body without being infected

Question 20

Which of the following best describes the function of an exoenzyme produced by pathogenic bacteria?

Accepted Answer

To break down host tissues and facilitate infection

D311 Microbiology Study Guide: Core Concepts and Review

Guida di studio - Domande di pratica

Study guide - Flashcard